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Ohio Department of Transportation
Statewide Roadside Pollinator Habitat Program
Restoration Guidelines and Best Management
Practices
June 2016
Prepared By: Ohio Department of Transportation
1980 West Broad Street
Columbus, Ohio 43223
Davey Resource Group
A Division of The Davey Tree Expert Company
1500 North Mantua Street
Kent, Ohio 44240
Contributors: Ohio Pollinator Habitat Initiative (OHPI)
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMPs Page i
Table of Contents
Table of Contents
i. Table of Contents
ii. How to Use This Document
Project Overview and Federal Programs Project Overview .................................................................................................................... 1-2
Federal Pollinator Initiatives ................................................................................................. 1-2
Ohio Pollinator Habitat Policy and Background ODOT Guidance Statement .................................................................................................... 2-2
Previous ODOT Efforts .......................................................................................................... 2-2
Collaboration with Ohio Pollinator Habitat Initiative (OPHI) ............................................. 2-3
Addressing Public Perceptions ............................................................................................... 2-3
Pollinator Declines and the Benefits of Native Vegetation .................................................... 2-5
Using Rights-of-Way to Mitigate Pollinator Concerns .......................................................... 2-7
Guide for Roadside Pollinator Habitat Establishment and Maintenance Site Selection, Analysis and Inventory .................................................................................... 3-3
Site Identification through GIS Mapping of ODOT Rights-of-Way ......................... 3-3
Site-Specific Criteria for Pollinator Habitat Restoration ........................................... 3-3
To Plant or Not to Plant: Low or No-Mow Areas and the Rationale for Their
Selection ................................................................................................................... 3-11
Plant Selection ...................................................................................................................... 3-12
Natives vs. Non-Natives .......................................................................................... 3-12
Bloom Periods: Spring to Fall .................................................................................. 3-13
Resources for All Life Cycle Stages ........................................................................ 3-19
Roadside Seed Mixes for Various Applications .................................................................... 3-20
General Mixes .......................................................................................................... 3-20
Showy Mixes ........................................................................................................... 3-23
Flowering Trees and Shrubs .................................................................................... 3-23
Site Preparation and Planting Methods ............................................................................... 3-24
New Construction or Specialty Sites ....................................................................... 3-24
No-Till ...................................................................................................................... 3-28
Post-Establishment Maintenance and Best Management Practices .................................... 3-31
Plant Life Cycles, Wildlife Nesting Seasons, and Mowing ..................................... 3-31
Noxious Weed Control: Utilizing Herbicides .......................................................... 3-32
Identify Problem Areas ............................................................................................ 3-32
Selective Application Methods ................................................................................ 3-36
Short-Term Maintenance during Establishment ...................................................... 3-38
Long-Term Maintenance Post-Establishment .......................................................... 3-39
Evaluating Pollinator Habitat Success ................................................................................ 3-41
Evaluating Plant Species Abundance and Diversity ................................................ 3-41
Evaluating Invertebrate Species Abundance and Diversity ..................................... 3-42
Frequently Asked Questions about Roadsides as Habitat for Pollinators
Statewide Roadside Pollinator Program Evaluation Forms
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMPs Page ii
How to Use this Document
How to Use this Document
This document has been developed to serve as a guide for
Ohio Department of Transportation (ODOT) District
managers and maintenance staff to establish and maintain
highway pollinator habitat within ODOT rights-of-way
(ROWs) throughout the State. This document can also be used
by Local Public Agencies (LPAs) as a guide for the
establishment of pollinator habitats along local roads within
their jurisdictions. By providing practical information that
managers can use to analyze and identify potential growing
sites and other essential criteria that should be taken into
consideration when designing a pollinator site, ODOT and LPAs can establish habitat for pollinators
while reducing annual maintenance costs that are incurred due to traditional mowing practices. This
document provides recommendations on selecting a native seed mix that is best suited for specific
site characteristics. Post-establishment maintenance and monitoring protocols are also presented to
help guide ODOT staff and LPAs in utilizing best management practices (BMPs) when maintaining
these sites.
This document has been divided into four sections to provide quick and easy references for both
management and maintenance staff. The first section, Project Overview, introduces users to the
reasons behind this initiative and identifies the goals of the interagency Pollinator Health Task Force,
the White House Pollinator Health Strategy documents, H.R. 22-110, Fixing America's Surface
Transportation (FAST) Act, and H.R. 2738, Highways Bettering the Economy and Environment
Pollinator Protection Act (Highway BEE Act). This section will explain the federal initiatives that
guided the policies and practices found in this document. This section is useful to those who wish to
find information on these policies and who need to reference the overarching goals behind ODOT’s
program and these federal initiatives.
The second section, Ohio Pollinator Habitat Policy and Background, provides users with ODOT’s
Guidance Statement and information on previous efforts by ODOT to incorporate native vegetation
and sustainable management practices into their roadside maintenance regimes. This section also
provides information on the importance of pollinators, causes for population declines, benefits of
using integrated roadside management practices, and the use of highway ROWs to help mitigate
these concerns. This section will be most useful for staff looking for information on the policies
outlined in this document, including their implications in managing roadside vegetation.
The third section, Guide for Roadside Pollinator Habitat Establishment and Maintenance,
provides users with a step-by-step guide for selecting pollinator sites, native seed mixes, and
establishment methodology. This section also guides users through the short-term maintenance needs
of a newly established pollinator habitat, as well as the long-term maintenance practices required to
maintain good native cover and diversity. Finally, this section covers the recommended techniques
for monitoring and evaluating the success of roadside pollinator habitats. This section contains
information pertinent to maintenance staff, their managers, and ODOT contractors who will be
installing and maintaining these roadside pollinator habitats.
The fourth section, Frequently Asked Questions about Roadsides as Habitat for Pollinators,
provides users with information to answer some of the most commonly asked questions from the
public regarding the use of native plants as pollinator habitat along highway ROWs. This section will
be most useful to ODOT staff members who frequently have contact with the public, such as those
who lead public outreach events or those who address phone calls from members of the public with
questions or concerns about highway safety and programs.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMPs Page 1-1
Project Overview and Federal Programs
Ohio Department of Transportation
Statewide Roadside Pollinator Habitat Program
June 2016
Project Overview and Federal Programs
Table of Contents
Project Overview
Federal Pollinator Initiatives
Pollinator Health Task Force
The White House Pollinator Health Strategy
H.R. 22-110, the Fixing America's Surface Transportation (FAST) Act
HR 2738, Highways Bettering the Economy and Environment Pollinator Protection Act
(Highway BEE Act)
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMPs Page 1-2
Project Overview and Federal Programs
Project Overview and Federal Programs
Project Overview
Amid increasing concerns over the declines in pollinator
populations and health, and the negative impacts these declines
have on the agricultural industry and the State’s economy, the
Ohio Department of Transportation (ODOT) initiated a project
to develop a statewide initiative to protect pollinators by
establishing and maintaining pollinator habitat along roadways
within ODOT rights-of-way (ROWs) throughout the state.
Information included in this document was gathered from a
wide variety of scientifically-backed sources, peer-reviewed
research documents, and a wide array of stakeholders who
provided input based on their knowledge and experience, and
helped to guide the development of this document. The main
goals of this program as laid out in this document include:
1) Reducing roadside management costs through the use of Integrated Roadside Vegetation
Management (IRVM) practices, such as reduced mowing regimes and reduced pesticide use.
2) Increasing the available pollinator resources in Ohio by installing diverse mixes of native
grasses and wildflowers along roadsides in lieu of traditional, less diverse cool-season grass
plantings.
3) Improving the public perception and understanding of pollinator health issues and
disseminating information on ways these declines can be mitigated.
This document discusses the recent federal policies put in place to protect pollinator populations
across the U.S., and the efforts made by ODOT to incorporate IRVM practices into the existing
ROW management regimes. Furthermore, this document outlines the Best Management Practices and
Policies developed by ODOT to expand upon these practices and existing projects, and also sheds
light on the methodology used to establish and maintain roadside pollinator habitat.
This document was developed with assistance from Davey Resource Group, a division of The Davey
Tree Expert Company, and members of the Ohio Pollinator Habitat Initiative (OPHI), which includes
representatives from industry, governmental agencies, universities, and nonprofit organizations.
Meetings were held with several members of OPHI to gather feedback from these stakeholders
throughout the development process. The information included in this document regarding the
recommended best management practices was reviewed and discussed to ensure the most accurate
and current information was used This guide is a working document that will be updated with new
information as it becomes available and as additional data are collected on the outcomes of the
pollinator sites installed by ODOT.
Federal Pollinator Initiatives
In the United States, bees pollinate about 1/3 of all crops that we eat. This equates to $14 billion
annually (The Ohio State University 2015). When one considers all pollinators—bees, butterflies,
and other pollinating insects, birds, and mammals—the impact this group of animals has on the U.S.
economy jumps to as much as $27 billion (Losey and Vaughan 2006). In Ohio, pollinators are
valuable contributors to the economy and are important pollinators for many crops, such as squash,
tomatoes, blueberries, peaches, apples, cucumbers, cantaloupes, and bell peppers. In 2014, Ohio’s
high-value crops requiring pollination had an estimated production value of more than $66 million.
Photograph 1-1. Roadside pollinator
habitats can provide imperiled species,
such as the monarch butterfly, with
critical food and shelter resources.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 1-4
Project Overview and Federal Programs
Such crops included apples, pumpkins, cucumbers,
squash, strawberries, grapes, and peaches
(U.S. Department of Agriculture, National Agriculture
Statistics Service 2014).
Over the years, domesticated and wild bees, as well as
other pollinators, have declined dramatically due to
parasites, pesticides, and in the case of European honey
bees, Colony Collapse Disorder. In response to this
problem, President Barack Obama issued a Presidential
Memorandum on June 20, 2014, in which he called for the
creation of a federal strategy to promote the health of
honey bees and other pollinators in the United States. In
his memorandum, the President called on the formation of
a Pollinator Health Task Force to be co-chaired by the Secretary of Agriculture and the Administrator
of the U.S. Environmental Protection Agency (EPA). In addition to the Co-Chairs, the Task Force
also includes the heads, or their designated representatives, of many of the nation’s federal
departments, including the Department of Transportation (USDOT). The mission of the Task Force
was to:
1) Develop a Pollinator Research Action Plan to focus federal efforts on understanding,
preventing, and recovering from pollinator losses.
2) Develop a Public Education Plan for expanding and coordinating public education programs
outlining steps individuals and businesses can take to help address the loss of pollinators.
3) Develop plans to enhance pollinator habitat and subsequently implement such plans on
managed lands and facilities, consistent with each Task Force member’s mission and public
safety. This included:
a) Evaluation of permit and management practices on power line, utility, and other
rights-of-way and easements, to make any necessary and appropriate changes to
enhance pollinator habitat on federal lands through the use of integrated vegetation
and pest management and pollinator-friendly best management practices.
b) Supplementing existing agreements and memoranda of understanding with rights-of-
way holders, where appropriate, to establish and improve pollinator habitat.
c) Incorporating pollinator health as a component of all future restoration and
reclamation projects.
In May 2015, the White House Pollinator Health Task Force published the National Strategy to
Promote the Health of Honey Bees and other Pollinators. The strategy identifies three major goals:
Reduce honey bee colony losses and overwintering mortality to no more than 15% within 10
years.
Increase the eastern population of the monarch butterfly to 225 million butterflies through
domestic and international actions and public/private partnerships.
Restore or enhance 7 million acres of land for pollinators over the next 5 years through federal
actions and public/private partnerships.
Photograph 1-2. President Obama signed a
presidential memorandum to protect
pollinators in the United States (Official White
House Photo by Pete Souza).
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 1-4
Project Overview and Federal Programs
In response to the Presidential Memorandum on Pollinator Health, USDOT has committed to:
Developing plans to enhance pollinator habitat on USDOT facilities and lands.
Working with State DOTs and other local transportation entities to promote
pollinator-friendly practices and corridors.
Identifying opportunities to educate privately-owned railways, pipelines, and other
transportation-related facilities about the need to increase pollinator habitat.
On June 11, 2015, Representatives Alcee Hastings (D-FL) and Jeff Denham (R-CA) sponsored the
Highways Bettering the Economy and Environment Act (Highways BEE Act: H.R. 2738). The Act
directed the Secretary of Transportation to use existing authorities, programs, and funding to
encourage and facilitate Integrated Vegetation Management practices (IVM) and pollinator habitat
efforts by willing State DOTs and other transportation right-of-way managers. Under the Act, the
Secretary of Transportation would:
Encourage IVM practices on roadsides and other transportation ROWs, including reduced
mowing.
Encourage native plantings (resulting in enhanced development of habitat for pollinators).
Encourage “cooperative conservation” leveraging through partnerships and coordination with
stakeholders in support of pollinators and native plantings.
Conduct or facilitate research and demonstration projects on the economic and environmental
benefits and best practices for IVM, reduced mowing, and native plantings for pollinator
habitat.
Report to Congress on actions being taken and provide recommendations for further action.
The legislation also amended the existing eligibility account (Section 329) for control of noxious
weeds and establishment of native species, by adding “provision of habitat for pollinators.”
In December 2015, President Obama signed the Fixing America's Surface Transportation Act (FAST
Act, HR 22). The FAST Act authorizes $305 billion over fiscal years 2016 through 2020 for highway
and motor vehicle safety, public transportation, motor carrier safety, hazardous materials safety, rail,
and research, technology, and statistics programs. Section 1415 of the FAST Act borrows a provision
from the Highways BEE Act and directs the Secretary of Transportation to use existing authorities,
programs, and funding to assist IVM and pollinator habitat efforts by willing State DOTs. Language
was also added to a key funding eligibility account, making it clear that actions to provide “habitat,
forage, and migratory waystations for Monarch butterflies, other native pollinators, and honey bees”
are eligible for funding assistance (FHWA 2016).
Currently, State DOTs manage 17 million acres of land that has the potential to be converted to
pollinator habitat through IVM, including reduced mowing and strategic planting of native flowering
plants and grasses that are beneficial to pollinating insects, birds, and mammals. Establishing
pollinator habitat also has the added benefit of lowering roadside maintenance costs, due to the
reduced need for mowing and herbicide use.
For the past several years, Ohio Department of Transportation (ODOT) has experimented with the
establishment of pollinator habitats along its roadway rights-of-way at various locations throughout
the state. In 2016, ODOT began working with the Ohio Pollinator Habitat Initiative and Davey
Resource Group to develop a GIS database of ODOT ROW corridors, including tree canopy cover
and land use designations for the entire state of Ohio. Additionally, pollinator habitat restoration
guidelines that can be used by ODOT districts and Local Planning Agencies to identify suitable areas
for pollinator habitat restoration within highway rights-of-way were also developed. These guidelines
provide recommendations for how to restore various types of pollinator habitats in these areas,
depending on existing soil conditions, slope, topography, solar exposure, and other contributing
factors.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 1-5
Project Overview and Federal Programs
Literature Cited
Losey, J. E., and M. Vaughan. 2006. The economic value of ecological services provided by
insects. Bioscience 56:311–23.
United States Department of Agriculture. May 2016. USDA’s National Agricultural Statistics
Services. 29 April 2016. https://www.nass.usda.gov/Statistics_by_State/Ohio/.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 2-1
Ohio Pollinator Habitat Policy and Background
Ohio Department of Transportation
Statewide Roadside Pollinator Habitat Program
June 2016
Ohio Pollinator Habitat Policy and Background
Table of Contents
ODOT Guidance Statement
Previous ODOT Efforts
Collaboration with Ohio Pollinator Habitat Initiative (OPHI)
Addressing Public Perceptions
Pollinator Declines and the Benefits of Native Vegetation
Using Rights-of-Way to Mitigate Pollinator Concerns
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 2-2
Ohio Pollinator Habitat Policy and Background
Ohio Pollinator Habitat Policy and Background
ODOT Guidance Statement
Pollinators such as bees, moths, and butterflies have been in serious decline around the world and in
the United States. These declines threaten our world food supply. In 2015, the White House,
recognizing this environmental threat, released its National Strategy to Promote the Health of Honey
Bees and Other Pollinators. The strategy calls upon all federal agencies to develop their own plans to
protect pollinators. In response to this directive, the U.S. Department of Transportation (USDOT)
developed its own pollinator protection plan that seeks to enhance pollinator habitat on Department
facilities and lands, increase pollinator habitat along roadways, work with State Departments of
Transportation to promote pollinator-friendly practices and corridors, and identify opportunities to
educate privately-owned railways, pipelines, and other transportation-related facilities about the need
to increase pollinator habitat.
In keeping with USDOT’s Pollinator Protection Plan, the ODOT has developed its own guidelines to
promote the establishment of pollinator habitat along ODOT rights-of-way. The guidelines provide
ODOT Districts with the necessary tools to select and modify sites for the establishment of pollinator
habitats that do not compromise the safety of the travelling public.
Previous ODOT Efforts
Prior to recent federal initiatives, including the White House Pollinator Health Strategy and the
FAST Act, ODOT began working to incorporate integrated roadside vegetation management (IRVM)
practices into its highway ROW maintenance regimes by reducing mowing and installing native
plants in several sites throughout the state. In fall 2013, the “Saving Ohio’s Pollinators” initiative was
developed in response to the increasing losses of bees and other pollinators, including the loss of over
65% of Ohio’s commercial hives between 2013 and 2014 (Monarch Joint Venture 2015).
This statewide initiative evolved from one of the first sites to be converted to pollinator habitat in
Ohio (located in Darke County). Discussions for this pilot project began in 2011 as part of a
collaborative effort between Pheasants Forever, Ohio Department of Natural Resources (ODNR), and
ODOT to establish wildlife habitat, while also helping to reduce mowing and roadside maintenance
costs. The installation process began in 2013, with an herbicide application to kill the existing
vegetation, followed by installation of a cover crop and a mix of 3 native grass species and 16 forbs.
Sites were installed along US 23, with one site on the south side of US 23, between State Route 127
and 121, and a second site located east of Greeneville. The completed project includes 29 acres
extending along the US 23 ROW.
In spring 2014, ODOT undertook another project in Ross
County, near the fairgrounds along SR 207. As part of the
project, ODOT planted a variety of native prairie species to
restore the habitat and provide food for pollinators. Maintenance
staff prepared and planted two, 1-acre plots along the SR 207
corridor in Ross County. The ODOT team also created a
partnership with the Deer Creek Chapter of Pheasants Forever to
assist in establishing these habitats. After two growing seasons
since their establishment, the sites have been largely successful,
with many pollinators and birds observed having utilized the
site.
Photograph 2-1. The Ross County
wildflower planting along SR 207 in
June 2015.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 2-3
Ohio Pollinator Habitat Policy and Background
Following completion of the Ross County project, ODOT again formed a partnership with outside
organizations to implement a third pollinator project in Fairfield County, this time collaborating with
Dawes Arboretum and Fairfield County Soil and Water Conservation District to install pollinator
habitat at the US 33 and Coonpath Road interchange, as well as at the I-71 and SR 13 interchange.
These sites were planted in spring 2015, and five additional counties were slated for installation in
the fall.
These projects, along with several additional projects, have yielded valuable information on what
methods are best for establishing native wildflower stands along highway ROWs, and what practices
are most economically sustainable and replicable. This knowledge is being used to drive this new
expanded initiative in order to establish a successful, long-term program in which the use of native
plant species and IRVM practices are used as a regular component of ODOT ROW management.
Collaboration with Ohio Pollinator Habitat Initiative (OPHI)
To help build upon previous efforts and further their goals of
completing additional projects, ODOT partnered with numerous
other state and private organizations in January 2015 to form
the Ohio Pollinator Habitat Initiative (OPHI), with the goal of
creating and improving pollinator habitat throughout the state of
Ohio.
OPHI is a statewide network of universities, non-profit
organizations, state and federal agencies, and private companies
that collaborate to provide education, outreach, research, hands-
on conservation, native seed collection, and technical assistance
to all that have an interest in pollinators and protecting our food
supply. This vast source of knowledge and experience from so
many different organizations allows OPHI to provide technical
advice, comprehensive reviews of existing literature, and specialized experts who can assist with
scientific studies of various types of pollinator habitats.
In May 2015, the Pollinator Health Task Force issued the National Strategy to Promote the Health of
Honey Bees and Other Pollinators, which initiated a goal to create 7 million acres of pollinator
habitat across North America by 2020. Ultimately, ODOT began leading OPHI in a much larger,
statewide initiative to begin implementing integrated roadside management practices that increase
pollinator habitat along ROWs through reduced mowing and installation of native wildflowers and
grasses. This project expands on the early pilot projects, using the lessons learned to create
management methods that can be applied to multiple sites across the state.
Addressing Public Perception
Although there are many financial, functional, and ecological benefits that result from using native
vegetation in highway rights-of-way, the general public may not be entirely receptive to the changes.
Some may view these naturalized areas as weedy and unkempt in appearance, while others may have
concerns about potential dangers to agricultural lands from harmful plant species, decreased motorist
safety, or increased collisions with wildlife.
Photograph 2-2. ODOT began
collaborating with organizations such as
Pheasants Forever and ODNR to form
OPHI in spring 2015.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 2-4
Ohio Pollinator Habitat Policy and Background
These are generally the views and opinions most often
heard by state DOTs, but these complaints represent only
a small portion of the entire population's perception and
should not be used to measure public perceptions about
utilizing native vegetation along highway ROWs. Public
opinion surveys can provide a more accurate measure of
public perception. In other states where such surveys
were conducted, many motorists are receptive to using
IRVM practices as long as it helps increase highway
safety (Guyton et al. 2014).
Some possible solutions for resolving negative public
perception include initiatives such as educating the public to help them better understand the many
ecological and economic benefits of managing roadsides for native vegetation using IRVM practices.
It can also be beneficial to form partnerships utilizing other agencies and organizations, such as
OPHI, to help conduct public education and outreach events. Finally, installing showy plantings in
high visibility areas and incorporating them into the State's tourism campaign can help generate
public interest and further the economic benefits of these roadside pollinator habitats.
Effective communication with the public is key to the success and perception of roadside restoration
projects. This includes both the general public and adjacent land owners who may perceive native
plants as a potential threat to their properties and farming operations (i.e., milkweed is perceived as a
problematic weed because it is toxic to livestock). Another key component to a successful pollinator
habitat program is staff awareness. Staff that could potentially have contact with the public should be
provided with proper training to help the public understand the goals and practices of the program.
Staff members should also be provided with the tools to adequately explain the program, answer
questions, and resolve complaints from the public.
Included in the fourth section of this document is a list of frequently asked questions (FAQs) that
have been developed to assist ODOT staff in providing concise, scientifically based answers to some
of the common questions and concerns from the public when implementing integrated roadside
management programs.
There are also many additional ways to raise public awareness and gain support. Such methods have
been used by other states with pollinator programs and include:
Providing educational information through web sources (i.e., social media, blogs, etc.),
brochures, posters, roadside signage, community meetings, or press releases.
Developing public service announcements (PSAs) to air on local radio stations and television
networks.
Offering promotional items such as license plates, wildflower handbooks, seed packets, or tee
shirts that could be purchased to help support and fund the program, while raising awareness.
Identifying groups that can provide support to the program, such as native plant societies,
garden clubs, and tourism organizations.
Working with groups that work with farmers, such as extension offices, to act as a liaison to
the agricultural industry.
Promoting wildflower tourism through development of materials (such as a Roadsides in
Bloom calendar), photography contests, and other public involvement events and materials.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 2-5
Ohio Pollinator Habitat Policy and Background
Pollinator Declines and the Benefits of Native Vegetation
Pollinator populations are in decline across the globe, putting agricultural yields and our overall
ecosystem health at risk. Bees and other pollinators are integral to maintaining vegetation
communities throughout the world that provide food and shelter for us and most wildlife. With as
much as 85% of all flowering plants dependent on pollination for survival, it is critical that steps be
taken to help reverse the decline in pollinator populations (Ollerton et al. 2011).
Pollinators are estimated to provide as much as $27 billion in crop pollination services in the U.S.
each year, which equates to one-in-three mouthfuls of food and drink that we consume. More than
two-thirds of our agricultural crop species are dependent on pollination, including many fruits,
vegetables, nuts, and even your morning coffee (McGregor 1976; Morse and Calderone 2000; Klein
et al. 2006; Losey and Vaughan 2006).
When most people think of pollinators, the domesticated European
honey bee is what usually first comes to mind; however there are
nearly 4,000 species of wild, native bees in North America that are
also very important crop pollinators (Michener 2007). Of the
hundred or so crops that comprise most of the world's food supply,
only 15% are pollinated by domestic honey bees, while at least 80%
are pollinated by wild bees and other wildlife (Prescott-Allen and
Prescott-Allen 1990; Buchmann and Nabhan 1996; Ingram et al.
1996a). Other native North American pollinators include 800
species of butterflies, as well as a number of flies, beetles, and other
insects, birds, bats, and other mammals (NatureServe 2014).
In recent years, honey bee populations have steeply declined, with
annual losses of 29% or more, due to a number of factors such as disease, pesticides, and habitat loss,
which are thought to lead to Colony Collapse Disorder (Bee Informed Partnership 2014). Less data
are available regarding the decline in native bees and other pollinator populations, but studies suggest
that their losses are similar or even greater than those of the honey bees, including significant
declines in 25% of North American bumblebee species (Hatfield et al. 2014). Eastern monarch
populations have declined by 90%, while western populations have seen a 50% decline due to loss of
milkweed sources, overwintering habitat, and extreme weather (Monroe et al. 2014; Rendon-Salinas
and Tavera-Alonso 2014; Jepsen et al. 2015).
Native bees are responsible for providing an annual value of as
much as $3 billion in crop pollination services in the U.S. (Losey
and Vaughan 2006; Calderone 2012). Many of these species are
specialists, pollinating only particular crops such as squash or
berries, and are often much more efficient at doing so than the
honey bee because they are specifically adapted for specific plant
types (Tepedino 1981; Bosch and Kemp 2001; Javorek et al.
2002; Garibaldi et al. 2013). The loss of these species can have
huge impacts on our global food resources. Furthermore, these
pollinator declines can result in detrimental effects on the overall
ecosystem health, including negative effects on plant reproduction
and plant community diversity (Brosi and Briggs 2013).
Enhancement and establishment of native habitat helps provide
the food and nesting resources needed to improve pollinator
populations.
Photograph 2-3. European
honeybees pollinate 15% of the
world's crops, while native bees and
other wildlife pollinate 80%.
Photograph 2-4. Squash bees
(Peponapis pruinosa) are native bees
that only pollinate plants in the squash
family.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 2-6
Ohio Pollinator Habitat Policy and Background
Native plants have many ecological benefits. They provide habitat, stabilize the soil, increase
stormwater infiltration (less runoff), replenish the water table, and sequester carbon (Quales 2003).
Native species are well adapted to local site conditions and are able to establish with little site
preparation and maintenance, compared to non-native turfgrass, which is traditionally planted along
roadsides. Native forbs and grasses also have much more well-developed, deep root systems that
stabilize the soil and prevent erosion; and they do not require the fertilizers, water, and other care
during establishment that non-native plants require (Quales 2003). Many species of native plants also
have a competitive edge that allows them to tolerate the poor, compacted soils found along roadsides.
In terms of benefits to roadside management practices, native plants also provide significant cost
savings in the maintenance of highway rights-of-way. Using native species significantly reduces the
need to mow beyond the clear-zone (safety-zone). Currently, ODOT mows over 290,000 acres of
highway right-of-way at a rate of four times per year in rural areas and as often as six times per year
in more urban settings. Costs are estimated at approximately $5.86 million each year. Native
pollinator habitats require mowing only once each year to maintain plant diversity, resulting in
significant cost savings. Furthermore, blanket herbicide applications made to roadsides could be
reduced as well. Native plantings help decrease weed pressure and can be managed through the use
of targeted spot-spray applications as needed to control non-natives. These savings, combined with
the savings resulting from reduced stormwater damage and erosion, are a great benefit of utilizing
native vegetation in highway rights-of-way.
Finally, the use of native plant species with vibrant colors provides an aesthetically pleasing
appearance along roadsides. This provides tourists and daily drivers with a more appealing and
stimulating view during their commute. Studies have shown that roadsides with native grasses,
wildflowers, and pollinators are more attractive to motorists and tourists overall. In Mississippi, 90%
of the motorists that were surveyed preferred to see native grasses and wildflowers along roadsides,
as opposed to traditional turf grasses (Guyton et al. 2014; FHWA 2015).
Figure 2-1. Native plants have extensive root systems compared to cool-season turfgrasses such as
Kentucky bluegrass (Illustration by Heidi Natura of the Conservation Research Institute).
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 2-7
Ohio Pollinator Habitat Policy and Background
Using ROWs to Mitigate Pollinator Concerns
With so many threats facing pollinator populations, the key to
slowing their decline lies in the conservation of existing habitats
and the creation and enhancement of additional ones. Roadsides
present a unique opportunity to slow the decline of pollinators
by converting low-diversity, frequently mowed areas dominated
by cool-season grasses to high-diversity wildflower and grass
habitats that provide much needed foraging, breeding, and
nesting habitat for pollinators. Not only do ROWs provide
valuable habitat, these areas also act as wildlife corridors that
link habitat fragments and aid in the dispersal of pollinators and
other wildlife (Ries et al. 2001; Hopwood et al. 2010). Utilizing
roadsides also presents an advantage in a society where land use
is at a premium. In some areas, it can be difficult to find open
land, where future development is unlikely in any significant quantity. But with more than 17 million
acres of state-managed highway ROW in the U.S., roadsides offer a massive network of linear
habitat for pollinators (Ament et al. 2014).
Roadsides have the potential to support all life-cycle stages by including both host and nectar plants,
as well as nesting and overwintering habitat for pollinators. By including a variety of plant species
and types, such as trees, shrubs, grasses, and forbs that have a variety of floral morphologies, color,
and height, with bloom periods that extend and overlap throughout the season, a wide variety of
pollinators are able to utilize the site. This variety not only helps maintain healthy populations of
native butterflies and bees, but also provides health benefits to managed honeybee populations by
increasing their immune system health (Di Pasquale et al. 2013).
Establishing these native habitats along highway ROWs
also provides habitat for a variety of other wildlife, such as
pheasants and wild turkeys. While beneficial to these
animals, establishing native habitats can cause safety
concerns with regard to collisions between vehicles and
wildlife, especially deer. However, studies indicate that the
presence of tall vegetation does not increase deer-related
collisions. For example, Indiana DOT monitored mammal
and bird mortality for a year after planting shrubs along
roadsides and found no significant increase in collisions
(Roach and Kirkpatrick 1985). Deer in particular prefer to
browse on new growth, which is created by frequent
mowing, as opposed to the less palatable older growth
(Mastro et al. 2008). Reduced mowing practices along highway rights-of-way may discourage deer
from browsing along roadsides, and taller vegetation may provide a more secure feeling for deer than
turfgrass, resulting in less deer bolting across roadways.
Many states, including Iowa, Minnesota, Indiana, Washington, and Florida, have implemented
successful programs to manage ROWs for pollinator habitat. These programs have been shown to
increase the number of wildflowers and other native plants (thereby increasing the number of
pollinators along ROWs) and to reduce the costs associated with mowing without any negative
impacts to normal highway operations.
Photograph 2-6. Deer tend to prefer frequently
mowed vegetation, as it provides more
palatable browse.
Photograph 2-5. More than 17 million
acres of right-of-way along highways,
such as the Ohio Turnpike, can be
converted to pollinator habitat.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 2-9
Ohio Pollinator Habitat Policy and Background
Literature Cited
Ament, R., J. Begley, S. Powell, and P. Stoy. 2014. Roadside Vegetation and Soils on Federal
Lands-Evaluation of the Potential for Increasing Carbon Capture and Storage and
Decreasing Carbon Emissions. Report for the Federal Highway Administration, #
DTFH68-07-E-00045. Available: http://www.westerntransportationinstitute.org/
documents/reports/4W3748_Final_Report.pdf. Accessed May 2016.
Bosch, J. and W.P. Kemp. 2001. How to manage the blue orchard bee as an orchard pollinator.
Sustainable Agriculture Network, National Agricultural Library; Beltsville, MD.
Brosi, B.J. and H.M. Briggs. 2013. Single pollinator species losses reduce floral fidelity and plant
reproductive function. Proceedings of the National Academy of Sciences of the United
States of America 110.32:13044-48.
Buchmann, S.L. and G.P. Nabhan. 1996. The Forgotten Pollinators. Washington, DC: Island
Press.
Calderone, N.W. 2012. Insect pollinated crops, insect pollinators and US agriculture: trend
analysis of aggregate data for the period 1992-2009. PloS one 7.5:e37235.
Di Pasquale, G., et al. 2013. Influence of pollen nutrition on honey bee health: do pollen quality
and diversity matter?. PloS one 8.8:e72016.
Garibaldi, L.A., et al. 2013. Wild pollinators enhance fruit set of crops regardless of honey bee
abundance. Science 339.6127:1608-11.
Guyton, J., E. Entsminger, and J. C. Jones. 2014. Alternative Mowing Regimes’ Influence on
Native Plants and Deer. Report No. FHWA/MDOT-RD-14-228.
Hatfield, R.G. and G. LeBuhn. 2007. Patch and landscape factors shape community assemblage
of bumble bees, Bombus spp. (Hymenoptera: Apidae), in montane meadows. Biological
Conservation 139.1:150-58.
Hopwood, J., et al. 2015. Literature Review: Pollinator Habitat Enhancement and Best
Management Practices in Highway Rights-of-Way. Federal Highway Administration
Publication.
Hopwood, J.L. 2013. Roadsides as habitat for pollinators: management to support bees and
butterflies. Proceedings of the 7th International Conference on Ecology and
Transportation (IOECT): Canyons, Crossroads, Connections. Scottsdale, Arizona, USA.
Hopwood, J.L. 2008. The contribution of roadside grassland restorations to native bee
conservation. Biological Conservation 141:2632-40.
Javorek, S.K., K.E. Mackenzie, and S.P. Vander Kloet. 2002. Comparative pollination
effectiveness among bees (Hymenoptera: Apoidea) on lowbush blueberry (Ericaceae:
Vaccinium angustifolium). Annals of the Entomological Society of America
95.3:345-51.
Jepsen, S., D. F. Schweitzer, B. Young, N. Sears, M. Ormes, and S. H. Black. 2015.
Conservation Status and Ecology of Monarchs in the United States. 36 pp. NatureServe,
Arlington, Virginia, and the Xerces Society for Invertebrate Conservation, Portland,
Oregon.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 2-10
Ohio Pollinator Habitat Policy and Background
Klein, A.M., B. E. Vaissière, J. H. Cane, I. Steffan-Dewenter, S. A. Cunningham, C. Kremen,
and T. Tscharntke. 2006. Importance of pollinators in changing landscapes for world
crops. Proceedings of the Royal Society Series B: Biological Sciences 274:303–313.
Losey, J. E. and M. Vaughan. 2006. The economic value of ecological services provided by
insects. Bioscience 56:311–23.
Mastro, L. L., M. R. Conover, and S. N. Frey. 2008. Deer-vehicle collision prevention
techniques. Human-Wildlife Conflicts 2(1): 80-92.
McGregor, Samuel Emmett. 1976. Insect pollination of cultivated crop plants. Vol. 496.
Agricultural Research Service, US Department of Agriculture.
Michener, C.D. 2000. The bees of the world. Vol. 1. JHU Press.
Monarch Joint Venture. 2015. http://monarchjointventure.org/. 8 May 2016.
Monroe, M., D. Frey, and S. Stevens. 2014. Western Monarch Thanksgiving Count Data from
1997–2013. Available: http://www.xerces.org/western-monarch-thanksgiving-count/.
Accessed May 2016.
Moroń, D., et al. 2012. Abundance and diversity of wild bees along gradients of heavy metal
pollution. Journal of Applied Ecology 49.1: 118-25.
Prescott-Allen, R. and C. Prescott-Allen. 1990. How many plants feed the world? Conserv. Biol.
4(4):365-374.
Quales, W. 2003. Native plants and integrated roadside vegetation management. IPM Practitioner
25(3-4):1-9.
Rendón-Salinas, E., and G. Tavera-Alonso. 2014. Forest surface occupied by monarch butterfly
hibernation colonies in December 2013. World Wildlife Fund–Mexico report. Available
from http://worldwildlife.org/publications/forest-surface-occupied-by-monarch-butterfly-
hibernationcolonies-in-december-2013 (accessed May, 7 2016).
Ries, L., D. M. Debinski, and M. L. Wieland. 2001. Conservation value of roadside prairie
restoration to butterfly communities. Conservation Biology 15:401-11.
Roach, G. and R. Kirkpatrick. 1985. Wildlife use of roadside woody plantings in Indiana. In
Transportation Research Record 1016:11-15
Tepedino, Vincent J. 1981. The pollination efficiency of the squash bee (Peponapis pruinosa)
and the honey bee (Apis mellifera) on summer squash (Cucurbita pepo). Journal of the
Kansas Entomological Society. 359-77.
United States Department of Agriculture. April 2009. National Agricultural Statistics Service.
United States Department of Agriculture. Natural Resources Conservation Service.
Pollinator Biology and Habitat.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-1
Guide for Roadside Pollinator Habitat Establishment and Maintenance
Ohio Department of Transportation
Statewide Roadside Pollinator Habitat Program
June 2016
Guide for Roadside Pollinator Habitat
Establishment and Maintenance
Table of Contents
Site Selection, Analysis and Inventory
Site Identification through GIS Mapping of ODOT Rights-of-Way
Site-Specific Criteria for Pollinator Habitat Selection
To Plant or Not to Plant: Low or No-Mow Areas and the Rationale for Their
Selection
Plant Selection
Natives vs. Non-Natives
Bloom Periods: Spring to Fall Resources for All Life Cycle Stages
Roadside Seed Mixes for Various Applications
General Mixes
Showy Mixes Flowering Trees and Shrubs
Site Preparation and Planting Methods
New Construction or Specialty Sites No-Till
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-2
Guide for Roadside Pollinator Habitat Establishment and Maintenance
Post-Establishment Maintenance and Best Management Practices
Plant Life-Cycles, Wildlife Nesting Seasons, and Mowing
Noxious Weed Control: Utilizing Herbicides
Short-Term Maintenance During Establishment Long-Term Maintenance Post-Establishment
Evaluation of Habitat Success
Evaluating Plant Species Abundance and Diversity
Evaluating Invertebrate Species Abundance and Diversity
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-3
Guide for Roadside Pollinator Habitat Establishment and Maintenance
Guide for Roadside Pollinator Habitat Establishment and Maintenance
Site Selection, Analysis, and Inventory
Establishing pollinator habitat along highway rights-of-way can be a relatively simple process. If one
follows approved practices, has the appropriate tools, and a little patience, pollinator habitat
restoration efforts will be successful. This section of the document will provide insight and guidance
for determining the ideal site by identifying specific site characteristics that will help increase the
odds of success.
Site Identification Through GIS Mapping of ODOT Rights-of-Way
The first step towards establishing a roadside pollinator habitat is selecting the best place to put one.
To help ODOT Districts identify potential sites for pollinator habitat restoration, ODOT completed a
statewide analysis of the existing rights-of-way along major state roadways using GIS data and
mapping software. This included an evaluation of the existing vegetation and tree canopy layers,
management restrictions, future highway construction projects, and other factors that would help or
hinder a pollinator habitat installation project. When choosing specific sites for planting, it will be
necessary to conduct a thorough analysis of all potential planting areas using this existing GIS ROW
data.
Consideration should be given to sites that will not undergo major construction in the foreseeable
future, such as lane expansions. Additionally, potential sites should be reviewed for any existing
management restrictions, such as herbicide, mowing, or fill restrictions that may limit the ability to
establish or effectively manage a pollinator site. The ODOT ROW GIS database can be used to filter
out these sites, as well as those with tree canopy cover and other land use considerations. Once a
selection of available sites in the desired area are determined using these data, other criteria should
also be considered to determine the most suitable sites. These characteristics can be filtered using
additional GIS data layers for each county but will ultimately need to be ground-truthed using the
form included in section five to make the final selection.
Site Specific Criteria for Pollinator Habitat Restoration
Several characteristics need to be included in a site analysis when determining an ideal pollinator
habitat planting site. Such characteristics include: sunlight; existing vegetative cover; topography;
soil characteristics; off-site considerations; planting design; size; shape; and maintenance equipment
considerations. Each potential planting site should be individually analyzed based on these criteria,
and then compared to each other using the same criteria in order to determine the planting site that
will afford the project the most success.
Sun Exposure and Topography
When evaluating a potential site, the first important thing to consider is the amount of direct sunlight
the site receives each day during the growing season. Many native pollinator plants require a
minimum of six hours of direct sunlight per day to thrive, while other plants are more shade tolerant.
Evaluating this information will help determine what species will be most suitable for each site.
When making this determination, it is necessary to evaluate the slope-aspect of the site relative to the
sunlight exposure to ensure adequate sunlight. For example, a north-facing slope does not receive
direct sunlight for much of the day, while a south-facing slope receives more sunlight because the
slope is tilted toward the sun and isn't directly shaded by the earth itself.
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
West-facing slopes in many climates are usually subject to hot afternoon sun and drying winds but
can be suitable for grassland heavy plantings that can be utilized by ground nesting bees. Generally,
shade-intolerant plants will flower more and provide greater amounts of nectar and pollen when they
receive ample sunlight exposure.
Figure 3-1. Potential planting sites should be evaluated for the amount of sunlight exposure each day.
North-facing slopes typically get less sunlight than south-facing slopes.
Roadside rights-of-way provide four distinct microhabitats or eco-environments. They consist of the
shoulder, side-slope, ditch, and back-slope. These areas may have very distinct differences in soil
conditions and can have hydrology variations within each of these areas themselves. Look for
differences in soil moisture, soil texture, organic matter, and pH. Native seed selection can be custom
fit to thrive in each of these unique growing environments. Preference may be given to sites with
level topography from the establishment and maintenance standpoint. Sites that are more level can be
easily assessed by equipment for installation and maintenance.
Existing Vegetation
Existing vegetative cover within a proposed planting site is another important characteristic to
evaluate. This information determines the extent to which the site will need to be prepared for
planting through mowing, herbicide, or other vegetation control methods. This information is also
important because of the nature of native plant growth.
Evaluation:
When evaluating a right-of-way for sun exposure and topography, be sure to consider the
following factors for each site:
1) Evaluate the trees and shrubs growing on and near the potential site. Do they shade the
site at any point during the day? If so, how long?
2) Observe the area within the site where the direct sunlight will be obstructed. This can
include steep hillsides and areas adjacent to bridges and overpasses, buildings, and other
structures.
3) Determine how long the shade covers each area and what species are best suited to the
amount of sunlight available.
4) What is the degree/angle of the slope across the site?
5) What is the cardinal direction of the slope-face?
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
Native plants take much longer to establish above-ground growth. This is because these plants focus
their energy in the first three to four years towards establishing their extensive root systems, rather
than herbaceous above-ground growth. Meanwhile, non-native grasses and noxious weeds send up
their leaves and flowers more quickly, shading other plants, and outcompeting them for water,
nutrients, and space.
One important factor to consider when evaluating the existing vegetative cover is the growth habit of
the species present. All herbaceous (non-woody) plants can function as annuals, biennials, or
perennials. An annual plant is one that completes its entire life cycle in one growing season. Biennial
plants need two growing seasons to complete their life cycles. Perennial plants are herbaceous plants
that continue to sprout up each season from their hardy root systems. This is important because
treating biennial weeds typically requires different techniques than treating annuals.
Additionally, all herbaceous plants that grow in Ohio can also be grouped into two categories: cool-
season and warm-season plants. Cool-season plants, such as Festuca arundinacea (tall fescue) and
Poa pratensis (Kentucky bluegrass), are plants that have adapted to cooler temperatures and
generally grow best when soil temperatures are between 50 and 65°F, which generally occurs in the
spring and fall. Once the soil temperatures increase above 75°F, these species go dormant until cooler
temperatures return. Warm-season plants, on the other hand, will not sprout up from seed, grow to
maturity, flower, and seed until soil temperatures have exceeded 65°F. These plants thrive in hot
summer temperatures and also benefit from prescribed burn management, which can function to
warm the soils and help give these species an early jumpstart in the spring.
To evaluate a site for existing vegetation, at least two site visits will be needed to accurately
determine the types of plants present. The first site visit should occur in the spring, followed by a
second visit in the late summer. While visiting the site during the growing season, expect to see the
mature cool-season species in the spring, followed by the mature warm-season species growing in the
late summer. Assess the site for both mature plants and for rosettes, a circular arrangement of leaves
at similar heights, generally low to the ground, which can be indicators of biennial plants. Assessing
the existing plant species will reveal the content of the site’s seed bank and the steps needed to
properly prepare a site for planting.
Figure 3-2. Warm-season and cool-season grasses have opposite growing seasons
(Source: http://www.ipm.ucdavis.edu/TOOLS/TURF/ESTABLISH/seasongrth.html).
Each site should also be evaluated to determine if there are any noxious weeds or undesirable plant
species present. These types of plants tend to have an ecological advantage over our native plants.
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
A complete list of the prohibited noxious weeds is provided in Ohio Administrative
Code 901:5-37-01. Other undesirable species would include any non-native, or invasive species such
as Phragmites australis (common reed) and Alliaria petiolata (garlic mustard). The presence of these
species of plants within a potential pollinator site should be classified into a percent cover range. A
percent cover of more than 50% for one or more undesirable species should not be considered as a
good candidate for a pollinator site, due to the extensive efforts that will be required to eradicate the
nuisance species and manage the site for long-term success.
Evaluating the species present at a potential site can also provide clues about soil pH and hydrologic
conditions. Soil pH is a numeric measure or scale of the acidity or alkalinity of the soil. This can
generally be determined from a basic soil test. The pH scale runs from 0 to 14. A pH of 7 represents a
neutral or balanced soil. Measures below 7 indicate an acid condition, while measures above 7
represent an alkaline or basic soil conditions. For comparison, vinegar has a pH of 2, which is very
acidic. Ammonia has a pH of 13, signifying it is very alkaline. Soil pH is greatly affected by the
bedrock which lies under the topsoil. Generally, soils in the eastern half of the state lie on top of
sandstone and are predominantly acidic, while topsoil in the western half of Ohio lies on bedrocks of
limestone and is naturally neutral to alkaline. However, site-specific conditions may vary. Soil pH
can influence the species of plants currently on a site, as well as what species of native pollinator
plants will thrive there.
Areas with good native plant populations may be more suitable for establishing a pollinator planting
than areas with well-established noxious/invasive plants. It is easier to renovate native plant
communities than it is to restore non-native monocultures.
Soil Characteristics
It is important to determine the type of soils within a potential planting site to ensure that the species
planted are able to thrive without soil amendments. Factors such as soil composition, hydrology, bulk
density, and nutrient content should be considered and can be easily determined by sending samples
from a potential site to a soils testing facility. Native grasses and wildflowers are well adapted to a
wide variety of soil conditions, but information on existing soil characteristics will help determine
the most ideal sites for pollinator habitat establishment.
Evaluation:
The following questions should be considered in relation to the existing vegetation cover.
1) Does the existing vegetation cover appear healthy?
2) Is the stand of vegetation cover thick and dense or thin and sparse? What percentage of
bare ground is present?
3) Is the existing vegetation cover predominantly comprised of annual, biennial, or perennial
plants? What is the percent cover of each?
4) Is the existing plant community at the site comprised of native or non-native species, or a
mixture of each? What is the percent cover of each?
5) Is the site predominantly occupied by cool-season or warm-season species?
6) Are there any noxious/invasive plants growing on or near the site? What are they? What is
their percent cover?
6)
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
Soil Composition
One major component of soil is its composition. Soil is comprised of various amounts of sand, silt,
clay, and organic matter. Sand, silt, and clay particles are different sizes, with sand being the largest
and clay the smallest; the percentage of these elements present in the soil determines what is called
the soil texture. The density of these particles and the airspaces between them dictate the ability of
soil to hold or drain water. For example, sandy soil matrices contain large pore spaces and drain
water quickly, while soils that are predominantly clay have small pore spaces and tend to hold water
more readily. Most native plants are tolerant of many soil conditions and soil types. However,
species that are well suited to the soil conditions present at a site should be selected to ensure
success.
Organic Content
Another important soil component is organic matter content, which is usually found in the upper
2 inches of the soil layer. Organic matter is decomposed material that was once living, i.e.,
decomposed plant and animal debris, and is rich in nutrients that become available to plants as the
organic layer breaks down. In rights-of-way that have had vegetation established for many years,
organic matter will be present to some degree in the upper layer of the soil profile. However, in new
construction sites, organic matter will be largely absent and the soil’s layers will be mixed and
compacted, reducing the permeability and water-carrying capacity. Soils that contain clay and
organic matter tend to absorb and hold on to water and nutrients longer than soils that are
predominantly gravel and sand. Soil moisture and fertility is most critical during early plant
establishment. As the habitat matures, few if any inputs, such as water or soil amendments, should be
required, especially if native plants are selected.
Soil Hydrology
Soil hydrology refers to how well soil can absorb and transfer water underground. Soils are classified
by the Natural Resource Conservation Service into four Hydrologic Soil Groups based on the soil’s
runoff potential. The four Hydrologic Soils Groups are A, B, C, and D. For the most part, group A
soils have the smallest runoff potential and group D soils have the greatest. When soil is saturated, it
cannot absorb any more water. At this point, water runs off the site and erosion can occur. Different
types of hydrology support different plant communities. In a roadside setting, the ditch will retain
water for a longer period of time than the side- and back-slope. There are many available pollinator
plants that are suitable for very wet and very dry sites. With this in mind, all native plants establish
better and thrive when matched with their preferred conditions. Therefore, planning should
emphasize those plants that will best adapt to the hydrologic soil conditions on the site.
Soil Fertility
Soil fertility is a measure of plant nutrients in the soil. Plant nutrients are chemical elements found or
introduced to the soil to promote plant growth. There are 14 essential plant nutrients. The three
primary nutrients are nitrogen (N), phosphorus (P), and potassium (K). There are also three
secondary nutrients that plants require for good growth; they are calcium (Ca), sulfur (S), and
magnesium (Mg). The micronutrients or trace minerals are boron (B), chlorine (Cl), manganese
(Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo) and nickel (Ni). The last two essential
nutrients that plants require are oxygen (O) and carbon (C), which are absorbed from the air. Most
Ohio soils provide sufficient amounts of these nutrients to support plant growth. Soil fertility will be
most critical during early plant establishment. As the habitat matures, few if any additional nutrient
inputs will be required.
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
Soil Contaminants
Many pollutants can also be found in the soils along the highway ROW, including deicing salts,
heavy metals, motor fuel, oil leachates, grease, and other pollutants, all of which can negatively
impact pollinator habitat establishment and growth. Studies have shown that these pollutants are
present in high levels adjacent to roadways. These pollutants typically decline around 20 meters (65
feet) away from the road. Some pollutants can persist as far as 200 meters (656 feet) from the road
(Spellerberg 1998; Trombulak and Frissell 2000). Pollinators can be exposed to these pollutants
through direct contact, or by ingesting contaminated plants, pollen, nectar, or water. Heavy metals
can accumulate in the bodies of honey bees (Perugini et al. 2011), and pollen contaminated with zinc
has been demonstrated to reduce reproduction and survival of mason bees (Moroń et al. 2010). Wild
bee diversity and abundance has been shown to decrease in meadow sites as heavy metal
concentrations increase (Moroń et al. 2012). However, very little is known about the long-term
impacts of these pollutants on pollinators.
Adjacent Land-Use Considerations
In addition to the physical characteristics of the site, it is
also important to consider the condition of the adjacent
properties. How the adjacent land is managed can play an
important role in the success of a pollinator planting site.
Situating a new site adjacent to a large agricultural field can
have both positive and negative effects. For example, a
large soybean field will likely be heavily managed with
pesticides and herbicides to protect the crops. This can
result in pesticide drift impacting an adjacent pollinator
habitat, which can negatively affect the plants and insects.
On the other hand, the pollinator habitat creates a buffer at
the edge of this field, providing food and nesting resources
in an otherwise monotypic vegetative community, and
helping to filter out some of the excess pesticide and
nutrient runoff, keeping it out of nearby waterways.
Photograph 3-1. Large agricultural farms often
use pesticides to maintain their crop fields,
which can inadvertently impact pollinator
habitats. (Photo courtesy of USDA NRCS)
Evaluation:
Answer the following questions when assessing the soils at a potential site:
1) What is the primary composition of the soil? Sand, silt, clay?
2) Is the soil dry and rocky? Loose and sandy? Compacted?
3) Has the area ever been used as a construction staging area? If so, are the soils excessively
compacted?
4) What is the overall hydrology of the soil? Does the site hold water for prolonged periods,
or does it dry out quickly? What is the seasonal duration of soil wetness (saturation or
inundation)? Is it well drained?
5) Has the soil from the site been recently tested by a lab to determine the nutrients present?
pH? Bulk density? What were the results?
6) How long has the site been vegetated since the previous disturbance (i.e., road
construction or agriculture)?
7)
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
Connectivity to other nearby pollinator habitats (e.g., prairie or forest) is important in providing
additional resources such as specific host plants, refuge, forage, and nesting space, to pollinators.
These areas may be good sites to build onto and create grouped habitats with similar management
regimes. Situating sites near existing pollinator habitat sites will not only help expand sites, but will
help maintenance staff more easily identify areas with reduced mowing regimes and avoid
unintentional mowing or spraying in these areas.
Site Design, Size, and Shape
Designing a pollinator habitat by incorporating information from the site analysis will help increase
the success of the planting. Next, let’s look at things to consider when determining the size and shape
of the habitat. Any size habitat can be beneficial to pollinators, but as a general rule of thumb, sites
should be 0.5 acre minimum. If habitat is fragmented and the distance between patches is greater
than the forging range of pollinators, then the benefits to pollinators are not as great. Research
suggests that a site of 2 acres or more will provide the greatest benefit and act as habitat corridors to
other existing habitats (Morandin and Winston 2006; Kremen et al. 2004.)
Pollinator plantings that take on a shape of large, square, or circular plots will minimize the edge
around the site, making it less susceptible to invasion by non-native and agricultural weeds from
outside of the perimeter. However, linear corridor plantings, such as along the back slope or a fence
row, will often be more practical. Where these linear plantings are used, consider a minimum width
of 3 meters (10 feet) (USDA NRCS New England Biology Technical Note, April 2009). Planting
areas should be designed to accommodate general roadside maintenance and mowing equipment by
providing enough space to easily maneuver around and mow the perimeter of the planting area. As
mentioned in the previous section, locating new pollinator habitats near existing native habitat
creates grouped habitats with similar management regimes, helping maintenance staff more easily
identify these areas and avoid unintentional mowing or spraying.
Evaluation:
When evaluating adjacent land uses, the following should be considered:
1) Observe the land adjacent to the potential pollinator planting site. Is the site adjacent to
large populations of non-native, invasive vegetation? This could result in increased
management costs associated with efforts to keep invasive vegetation out of the pollinator
habitats.
2) Is the site next to agricultural cropping operations? Inadvertent drift from pesticides used
for crop protection can negatively impact pollinator populations and plants that are
intended to attract pollinators.
3) Is the site adjacent to existing parks or other natural areas? These can be ideal sites to
build upon.
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Maintenance Equipment Considerations
Much of the same equipment on hand for roadside vegetation maintenance can be utilized to
maintain pollinator plantings. When using existing equipment, be sure all equipment is clean and free
of weed seed. Consider leaving a mow zone buffer between the road and the pollinator habitat that is
wide enough to maneuver mowing machinery without impacting the plantings.
When designing the shape of the pollinator habitat, be sure to consider the turning radius of the
tractor and mower. Designing a shape with hard angles and sharp curves could cause shaving of the
habitat perimeter with mowing equipment over time. Habitat planting designs that do not take
machinery capabilities into consideration require extra effort and time mowing the perimeter to keep
the grass looking maintained around the habitat. Keep things maintenance friendly by choosing
shapes and dimensions that are obtainable with existing mowing equipment.
Evaluation:
When establishing pollinator habitat, consider the following with respect to plot size, shape, and
location:
1) Is there an existing site with similar management regimes that the new site can be located
next to? (i.e., remnant wildflower plot or areas with existing mow restrictions)
2) Are there other existing wildflower and woodland habitats that can be linked together with
a new pollinator habitat? Either directly, or as a “stepping stone” to existing habitats?
3) Is there an area within the ROW that is large enough to accommodate a wider pollinator
habitat with reduced edge, such as an interchange area or rest stop? If the plot will be
linear, is there an area more than three meters (10 feet) in width?
Figure 3-3. Edge effect can be minimized by keeping planting sites
large and square or circular in shape.
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
Figure 3-4. Mowing can be more easily done in circular patterns,
preventing inadvertent mowing of pollinator habitat edges.
To Plant or Not to Plant: Low or No-Mow Areas and the Rationale for Their Selection
Not all sites will make good pollinator habitat sites, perhaps because the adjacent property has
agricultural crops planted to the edge of the right-of-way and pesticide drift would be too difficult to
control. Rather than writing these sites off completely, consider implementing management practices
that would foster naturally occurring native species, without the expense of planting wildflower seed.
While conducting initial site analyses, use the evaluation metrics discussed in the previous section
and the scorecard provided in section five to score all potential planting areas. Each site should have
its own scorecard. Once completed, compare the numeric scores of all sites and determine which
offer the best characteristics for a pollinator habitat planting. For those sites that do not score well in
the site analysis evaluation, or if the budget limits the number of sites able to be planted, consider an
IRVM program that focuses on reduced mowing and targeted herbicide use, rather than installation
of a wildflower mix. Many native plants beneficial to pollinators will naturally colonize a site when
not regularly mowed and managed for non-native weeds. These sites will also be easy to convert to
pollinator habitat in the future if possible.
Many states have adopted IRVM programs to promote an ecologically focused approach to roadside
vegetation management while maintaining a safe travel environment. An IRVM program should
include a reduced mowing regime of no more than two times per year. The timing of mowing
activities should center on the life cycles of the pollinators to minimize direct mortality of the insects,
and should also be done on a rotation within the same area to avoid removing all resources at the
same time. If possible, delay mowing until the fall, after the first killing frost, to allow for continuous
floral resources and access to nesting habitat. Throughout the growing season, employ proper timing
and targeted use of herbicides using spot-spray techniques to reduce impacts to pollinators and native
plants. Each site should adopt unique IRVM plans based on species present, and the non-native
weeds being managed.
Figure 3-5. Rotate mowing in different sections of the same planting to avoid removing all resources at once.
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
Plant Selection
With the best possible site(s) now chosen, it is time to select the plants for the pollinator habitat
planting. Vegetation planted along roadsides performs multiple functions. The planting is expected to
improve safe travel, be inexpensive to maintain, look attractive, stabilize and improve the soil, slow
down stormwater runoff, and provide environmental benefits. While non-native grasses such as
Lolium spp., fescues, and ryegrasses establish easily and are long lived, they do not provide many
environmental benefits. Endophyte infected tall fescue inhibits many soil organisms, including
pathogenic fungi, parasitic nematodes, and beneficial mycorrhizal fungi. The fescue endophyte
produces loline alkaloids that are toxic to at least 20 insect species from 10 families and 5 orders. The
endophyte also produces ergot alkaloids that are toxic to mammals including domestic livestock.
According to the Natural Resource Conservation Service, fescue also causes many problems for a
number of game birds. Tall fescue, which has replaced many acres of native grass, does not supply
the type of food and cover that many smaller game species need to thrive. For example, tall fescue
only supports a limited number of insects, which are an important food for both quail and turkey.
Further, when tall fescue is either mowed or grazed, it forms a thick, impenetrable mat near the soil
surface. Many birds, including dove and quail, are weak scratchers; tall fescue does not allow enough
bare ground for these birds to obtain adequate food or easily move through the habitat.
Developing a list of wildlife and pollinator friendly plant species should emphasize plants that
provide pollen and nectar-rich forage resources for bees, butterflies, hummingbirds, and bats. It is
essential these plant communities be diverse and not monocultures. The plant species selected should
include important larval food plants for butterflies and moths. If making a custom plant list, be sure
to include species that will provide consistent, overlapping flowering periods throughout the entire
season.
Finally, to increase the chances the pollinator habitat will survive over time, remember the 10-20-30
Rule, often used in woody ecosystems. It states that a managed plant community should contain no
more than 10% of a single species, no more than 20% of a single genus, and no more than 30% of a
single family in order to resist insect and disease epidemics (Santamour 1990).
Natives vs. Non-Natives
It is imperative to recognize that commercially available seed suppliers offer both native and
non-native seed. In many instances, non-native seed is less expensive and more widely available to
purchase. However, native plants are advantageous because they generally provide greater
environmental and economic benefits than non-natives. Furthermore, diverse plantings resembling
naturally occurring native plant communities are more likely to resist damage from pests, diseases,
weather extremes, and weed pressure than traditional turfgrasses used along highway ROWs.
Native plants offer the added benefit of being more adapted to local conditions, giving native
vegetation a competitive advantage over non-natives. Native species can typically establish more
quickly and with much more dense ground cover, but do not require fertilizers, require less water,
and are less likely to become invasive than non-natives. Native grass and forb species are also
preferred by pollinators over non-native species, generally providing higher quality food/nectar and
more abundant shelter resources. Native vegetation can also inhibit non-native weed encroachment
and promote local biological diversity. These factors, combined with reduced mowing and herbicide
use, often make native plantings significantly more cost effective in the long run.
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Bloom Periods: Spring to Fall
Another very important factor in choosing an appropriate
seed mix is selecting species that provide nectar and pollen
throughout the growing season. The growing season is the
time between the last frost in the spring and the first hard
frost of the fall. Records show that on average, the growing
season in Ohio is around 190 days, which can range from
early April to late October, depending on the specific
region. Considering all that needs to occur, i.e., plants
sprout, grow and flower, as pollinators feed and reproduce,
it’s a wonder how all this gets accomplished in just six
months. With that in mind, pollinator habitats need to
produce the maximum amount of food resources for the
longest amount of time during the growing season to benefit
the greatest number of pollinator species and other wildlife.
To encourage the greatest number and diversity of pollinators in the habitat, include a diversity of
plants with different flower color, sizes, and shapes as well as varying plant heights and growth
habits. Different pollinators have different preferences when it comes to the type of flowers they will
visit. For example, bees are most attracted to blues, purples, yellows, and whites, while butterflies
will often favor reds, in addition to the other colors (Procter et al. 1996). Flower morphology is also
important, as different pollinator species are adapted to specific types of flowers. Hummingbirds, for
example, require tube-shaped flowers on which to feed.
Include in the seed mix a diversity of flowering plants with sequential bloom times so that floral
resources are available to pollinators throughout the growing season. Early season pollen and nectar
sources will increase the success rate of pollinators that emerge early in the spring and begin nest-
building activities, while late blooming plants ensure that honeybees and other pollinators go into
winter with sufficient food reserves.
When choosing species for a seed mix, include three to four different species of flowering plants for
each bloom period, so that at any given time there are several different flower types to accommodate
a variety of pollinators. The chart included in Table 3.1 illustrates the bloom period, color, size, and
other characteristics for some of the most common native species, and can be used to choose species
that will provide the greatest benefits for a given site.
Photograph 3-3. Common milkweed (Asclepias
syriaca) blooms mid-season (June-August).
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Table 3.1. Master List
Species Name Common Name Plant Type Bloom
Period
Light
Requirement Water Tolerance Characteristics
Achillea millefolium common yarrow perennial forb June-Sept full sun dry to
medium deer, drought, dry soil
Allium cernuum nodding onion perennial forb June-Aug full sun to part
shade
dry to
medium
deer, drought, dry soil,
shallow-rocky soil
Aquilegia
canadensis
Eastern red
columbine perennial forb April-May
full sun to part
shade Medium rabbit, deer, drought, dry soils
Asclepias syriaca common
milkweed perennial forb June-Aug full sun
dry to
medium
deer, drought, erosion, dry
soil, shallow-rocky soil
Asclepias tuberosa butterfly weed perennial forb June-Aug full sun dry to
medium
deer, drought, erosion, dry
soil, shallow-rocky soil
Aster laevis smooth aster perennial forb Sept-Oct full sun dry to
medium
drought, erosion, dry soil,
shallow-rocky soil
Aster novae-angliae New England aster perennial forb Aug-Sept full sun medium clay soil
Aster umbellatus flat-topped white
aster perennial forb July-Sept
full sun to part
shade
medium to
wet
Baptisia alba white false indigo
herbaceous
perennial
(shrubby)
Apr-May full sun to part
shade
dry to
medium drought, erosion, dry soil
Baptisia australis blue false indigo
herbaceous
perennial
(shrubby)
May-June full sun to part
shade
dry to
medium
rabbit, drought, erosion, clay
soil, dry soil, shallow-rocky
soil
Chamaecrista
fasciculata partridge pea annual forb June-Sept full sun
dry to
medium drought, dry soil
Coreopsis
lanceolata lanceleaf coreopsis perennial forb May-July full sun
dry to
medium
deer, drought, dry soil,
shallow-rocky soil
Coreopsis tinctoria plains coreopsis annual forb June-Sept full sun dry to
medium
deer, drought, clay soil, dry
soil, shallow-rocky soil
Cosmos bipinnatus cosmos annual forb June-frost full sun Medium
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Species Name Common Name Plant Type Bloom
Period
Light
Requirement Water Tolerance Characteristics
Cosmos sulphureus sulphur cosmos annual forb June-Sept full sun dry to
medium drought, dry soil
Dalea candida white prairie
clover perennial forb May-June full sun Medium drought
Dalea purpurea purple prairie
clover perennial forb June-Aug full sun Medium drought
Desmodium
canadense showy tick trefoil perennial forb June-Sept full sun
dry to
medium
Echinacea
purpurea purple coneflower perennial forb June-Aug
full sun to part
shade
dry to
medium
deer, drought, clay soil, dry
soil, shallow-rocky soil
Eryngium
yuccifolium rattlesnake master perennial forb June-Sept full sun
dry to
medium
drought, erosion, clay soil, dry
soil, shallow-rocky soil
Gaillardia
pulchella indian blanket annual forb June-frost full sun
dry to
medium drought
Helianthus mollis ashy sunflower perennial forb July-Sept full sun dry to
medium
drought, dry soil, shallow-
rocky soil
Heliopsis
helianthoides ox-eye sunflower perennial forb June-Aug full sun
dry to
medium
drought, erosion, clay soil,
shallow-rocky soil
Hibiscus
moscheutos
swamp rose
mallow perennial forb July-Sept full sun
medium to
wet deer, wet soil
Iris versicolor northern blue flag perennial forb May-June full sun to part
shade
medium to
wet deer, wet soil
Iris virginica blue flag iris perennial forb June full sun medium to
wet deer, wet soil
Lespedeza capitata roundheaded
bushclover perennial forb July-Sept full sun medium
Liatris spicata dense blazingstar perennial forb July-Aug full sun medium drought, clay soil
Lobelia cardinalis cardinal flower perennial forb July-Sept full sun to part
shade
medium to
wet rabbit, deer, wet soil
Lobelia siphilitica great lobelia perennial forb July-Sept full sun to part
shade
medium to
wet deer, heavy shade, wet soil
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Species Name Common Name Plant Type Bloom
Period
Light
Requirement Water Tolerance Characteristics
Mimulus ringens monkey flower perennial forb June-Sept full sun to part
shade
medium to
wet deer, wet soil
Monarda citriodora lemon mint annual forb May-Aug full sun to part
shade
dry to
medium deer, drought
Monarda fistulosa wild bergamot perennial forb July-Sept full sun to part
shade
dry to
medium
deer, drought, clay soil, dry
soil, shallow-rocky soil
Nepeta racemosa catmint perennial forb April-Sept full sun to part
shade
dry to
medium
deer, drought, dry soil,
shallow-rocky soil
Penstemon digitalis smooth penstemon perennial forb April-June full sun dry to
medium
deer, drought, clay soil, dry
soil
Physostegia
virginiana obedient plant perennial forb June-Sept full sun medium deer, clay soil
Pycnanthemum
tenuifolium
narrow-leaved
mountain mint perennial forb July-Sept
full sun to part
shade
dry to
medium
drought, erosion, clay soil, dry
soil, shallow-rocky soil
Ratibida pinnata grey-headed
coneflower perennial forb June-Aug full sun medium drough, clay soil
Rudbeckia hirta black-eyed Susan perennial forb June-Sept full sun medium deer, drought, clay soil
Rudbeckia
subtomentosa
sweet black-eyed
Susan perennial forb July-Sept full sun medium
deer, drought, clay soil, dry
soil
Rudbeckia triloba brown-eyed Susan perennial forb July-Oct full sun medium deer, drought
Silphium
perfoliatum cup plant perennial forb July-Sept full sun
medium to
wet clay soil, wet soil
Solidago ohioensis Ohio goldenrod perennial forb July-Sept full sun dry to
medium deer, drought, clay soil
Solidago rigida stiff goldenrod perennial forb Aug-Sept full sum medium deer, clay soil
Solidago speciosa showy goldenrod perennial forb July-Sept full sun dry to
medium deer, drought, clay soil
Verbena hastata blue vervain perennial forb July-Sept full sun medium to
wet wet soil
Veronicastrum
virginicum Culiver's root perennial forb May-Aug full sun
medium to
wet wet soil
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Grasses, Sedges, and Rushes
Species Name Common Name Plant Type Bloom
Period
Light
Requirement Water Tolerance Characteristics
Avena sativa oats annual grass
(cover crop) June-July full sun
dry to
medium drought tolerant
Bouteloua
curtipendula side-oats grama
perennial grass
(warm season,
clump)
July-Aug full sun dry to
medium
drought, erosion, dry soil,
shallow-rocky soil
Carex comosa bristly sedge perennial sedge June full sun medium to
wet
Carex crinita fringed sedge perennial sedge May-June full sun to part
shade
medium to
wet deer, erosion, wet soil
Carex grayi grey's sedge perennial sedge May-Oct full sun to part
shade
medium to
wet deer, erosion, wet soil
Carex lurida lurid sedge perennial sedge May-June full sun to part
shade
medium to
wet deer, erosion, wet soil
Carex vulpinoidea brown fox sedge perennial sedge May-June full sun medium to
wet deer, erosion, wet soil
Elymus canadensis nodding wild rye
perennial grass
(cool season,
clump)
July-Sept full sun dry to
medium drought, erosion, dry soil
Lolium multiflorum annual rye grass annual grass
(cover crop) May-Sept full sun medium
Schizachyrium
scoparium little bluestem
perennial grass
(warm season,
clump)
July-Oct full sun dry to
medium
deer, drought, erosion, dry
soil, shallow-rocky soil
Schoenoplectus
tabernaemontani great bulrush perennial rush Apr-May full sun wet
Scirpus atrovirens dark green bulrush perennial rush June-July full sun to part
shade
medium to
wet wet soil
Scirpus cyperinus woolgrass perennial rush June-July full sun to part
shade wet wet soil
Secale cereale winter rye annual grass
(cover crop) May-July full sun medium drought tolerant
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
Species Name Common Name Plant Type Bloom
Period
Light
Requirement Water Tolerance Characteristics
Sporobolus
heterolepis prairie dropseed
perennial grass
(warm season,
clump)
Aug-Oct full sun dry to
medium
deer, drought, erosion, dry
soil, shallow-rocky soil
Tridens flavus purpletop perennial grass
(warm season) Aug-Nov partial shade dry
Triticum aestivum winter wheat annual grass
(cover crop) June-July full sun medium
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Resources for All Life Cycle Stages
Including plants that flower is not the only criteria
necessary when creating a pollinator habitat. It is also
important to include other plant types that provide
resources for all pollinator types and life cycle stages,
such as grasses, trees, and shrubs. While flowers
provide sources of pollen and nectar, other plants
provide nesting habitat and food sources for larvae of
other pollinators.
A primary example of this relates to butterflies and
moths. Most Lepidoptera species require host plants
for adults on which to lay their eggs.
Some butterflies are specialists, using only a single
species or genus of plant as their host plant, while others are generalists, using a wide array of plants.
The monarch butterfly is an example of an insect whose caterpillars feed only on species of Asclepias
spp. (milkweed), while members of the swallowtail family are able to utilize a variety of trees,
shrubs, and forbs. Establishing host plants is a way to ensure roadside habitats can support both the
generalist and specialist habitat requirements of these butterfly and moth species. Site placement and
species selection should take these requirements into consideration.
When selecting a pollinator site, it is also important to evaluate the surrounding vegetation and
determine if the site can be located near an existing woodland habitat. Many butterfly species utilize
woody plants as their host plant, and other pollinators, such as bees and bats, use forests as nesting
and refuge habitat; however, these plants are not a practical choice for roadside establishment due to
safety concerns over vehicle collisions with trees and wildlife that use forested sites. Locating a site
near an existing woodland habitat can provide these resources, without the need to establish them
directly.
Grasses, sedges, and rushes are another important factor in choosing a pollinator seed mix, and
provide additional food and nesting resources for pollinators. As much as 70% of North America’s
bee’s species nest in the soil (Michener 2007). Ground-nesting bees require open areas of soil
between the vegetation in which to excavate their nests, and the inclusion of native bunch grasses
provides better nesting habitat than sod-forming grasses. These bunch grasses, such as Schizachyrium
scoparium (little bluestem) and Sporobolus heterolepis (prairie dropseed), provide the space between
plants for bee nesting sites as well as space for other wildlife species, such as quail or pheasants, to
freely move through a habitat. Choose grass species that match the goals of the site and the level of
management that can be dedicated to it to ensure a well-balanced species diversity.
Utilizing a combination of grasses and wildflower species provides good soil stabilization, is
beneficial to pollinators, and can help resist weed colonization; however, when establishing habitat
specifically for pollinators, it is important to choose appropriate grass species. Some species of native
grasses are more aggressive and can dominate a site and lower the overall plant diversity of a site
over time. Avoid using species such as Panicum virgatum (switchgrass), which can easily overtake a
site within just a few years, and incorporate lower quantities of species such as little bluestem that
grow much more slowly and better coexist with forbs. A few recommended seed mixes can be found
in the following section for specific applications. District and garage managers can seek assistance
from ODOT’s Office of Environmental Services when determining what to plant where.
Photograph 3-4. Monarch caterpillars rely solely on
milkweed species until they become adult
butterflies.
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
Roadside Seed Mixes for Various Applications
There are a wide variety of commercial mixes available marketed as native or pollinator mixes.
However, it is important to consider that many of these mixes contain plant species that are not
native to Ohio, some of which are considered weeds, and cultivars of native plans, which can dilute
the gene pool of existing native plants in the area. These pre-made mixes also generally do not have
enough floral resources present throughout the growing season. These mixes generally contain plant
species that have high visual appeal, rather than pollen and nectar sources.
When choosing seed mixes, observe the species that already naturally occur near the planting area.
Plant species found growing alongside each other in local natural areas are likely to have the same
light, moisture, and nutrient needs. When these species are matched with each other in a seed mix
and then sown into roadside plantings that have similar characteristics as the nearby natural area, the
chances are more likely they will thrive where they are planted.
Look for these associations during the site analysis. By reviewing past ecological survey reports that
have been prepared for nearby projects, ODOT’s Office of Environmental Services may be able to
provide District Offices and highway maintenance crews with assistance in determining what plant
species are typically found in a given area.
General Seed Mixes
Seed dealers offer general, native seed mixes available for sale. These mixes usually are labelled as
Wet Meadow or Upland Meadow mixes. It is important to realize general seed mixes are developed
with species adapted to a specific habitat type. Plants that prefer wet areas are generally found in
wetland mixes. Similarly, plants that naturally grow on upland sites are contained in upland mixes.
With limited knowledge of native plants, one can rely on these mixes to include native plants that
will grow well in these general site conditions.
Figure 3-6. Survival rate of native wildflowers in compacted, roadside soils.
(Credit Anand Persad, The Davey Institute; for ODOT internal use only.)
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
Figure 3-7. Survival rate of native wildflowers in loamy soils.
(Credit Anand Persad, The Davey Institute; for ODOT internal use only.)
When using these general mixes for a pollinator habitat planting, be sure to review the list of species
in the mix to determine bloom time. It is recommended that a pollinator habitat contain a minimum
of at least three different pollinator plants that bloom within each of the three blooming periods.
The blooming periods are early spring, mid-summer, and early fall. Ideally, to maximize the benefits
to all pollinators, habitats should increase plant diversity to 20 or more different flower species.
Below are recommendations of plants to include for general wetland and upland sites that offer
optimum benefits to pollinators for Ohio.
Table 3-2. General Pollinator Habitat Seed Mix for Sunny, Mesic to Wet Sites (suitable for roadside
ditches, stormwater basins, and low-lying areas; colors denote bloom color)
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Table 3-3. General Pollinator Habitat Seed Mix for Sunny, Dry Upland Sites (suitable for hillsides,
well-drained, rocky soils, and other dry sites; colors denote bloom color.)
Table 3-4. Low-Cost Pollinator Habitat Seed Mix for General Roadside Use (suitable for most upland
roadside pollinator habitat applications; colors denote bloom color.)
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Showy Seed Mixes
Showy native seed mixes can be used anywhere along highway rights-of-way where increased
emphasis on aesthetics is desired. These areas may include roadside rest areas, highway entrances
into cities and towns, large interchange areas, and designated scenic routes. These types of pollinator
habitats have the added benefit of garnering public support for the pollinator habitat initiative.
Table 3-5. Showy Seed Mix for Sunny, Mesic Sites (suitable for sites with moderate moisture levels)
Flowering Trees and Shrubs
Woody plants offer many additional benefits to pollinators and can be used as hedgerows or buffers
between pollinator sites and adjacent agricultural land. Trees and shrubs are typically begin to bloom
prior to most herbaceous plants and provide valuable early-season food sources at a critical time
when pollinators are just beginning to emerge. Since woody plants also stop blooming earlier in the
season than other herbaceous vegetation, they should not be used as a primary source of pollinator
resources. Many species of trees and shrubs are wind pollinated; therefore, it is important to include
woody species that are known to be utilized and pollinated by insects.
Woody plantings can be used to enhance existing woodland habitat along rights-of-way, or as
supplemental plantings within herbaceous stands. These plantings will act as habitat corridors and
refuge for many pollinator species. As with herbaceous species, woody pollinator planting should
also contain at least three species for each of the three bloom periods for trees and shrubs. Woody
plantings can be established using bare-root seedlings, containerized, or balled and burlapped stock.
Some of the recommended species are shown in Table 3.6.
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Table 3-6. Tree and Shrub Species Beneficial to Pollinators.
Scientific Name Common Name Bloom Period Average Height
at Maturity (ft.)
Shade
Tolerance Form
Pollinator
Preference
Acer rubrum red maple
Very Early
(March -
April)
90 Tolerant Tree Bees
Sambucus canadensis elderberry 7 Intermediate Tree/Shrub Bees
Cercis canadensis eastern redbud 16 Tolerant Tree/Shrub Bees,
Butterflies
Prunus americana American plum
Early
(March -
May)
30 Intolerant Tree/Shrub Bees,
Butterflies
Diospyros virginiana persimmon 50 Tolerant Tree Bees
Nyssa sylvatica black gum 95 Tolerant Tree Bees
Prunus serotina black cherry 100 Intolerant Tree Bees,
Butterflies
Robinia pseudoacacia black locust
Mid
(May - July)
70 Intermediate Tree Bees,
Butterflies
Liriodendron tulipifera tulip tree 120 Intolerant Tree Bees,
Hummingbirds
Tilia americana American basswood 90 Intermediate Tree Bees,
Butterflies
Site Preparation and Planting Methods
Often overlooked or inadequately addressed, site preparation is one of the most important factors in
establishing a successful pollinator habitat. The site preparation step needs to be planned well in
advance of a project, as it can often take one or more seasons to properly prepare a site. Depending
on the site conditions, it is almost always necessary to apply herbicides and utilize mowing
equipment to reduce competition from non-native, undesirable vegetation prior to planting, with the
exception of newly graded (bare-earth) sites. Native seed should be planted by either conventional
(disking or broadcasting) or no-till methods. No-till methods are preferred because there is little soil
disturbance, reducing weed competition and soil erosion. Conventional methods can be used on areas
that have little weed pressure and low erosion risk. This section provides step-by-step instructions for
using these methods to prepare and plant sites with various conditions, and how to choose which is
most appropriate.
New Construction or Specialty Sites
Highway ROWs provide a unique opportunity for establishing native vegetation in place of the
traditional turfgrasses because of the regular road construction and maintenance activities that occur.
Large areas of freshly graded, bare soils are often left in the wake of new highways, interchanges,
and road expansions, which are generally seeded with a cool-season turfgrass mix. In these cases,
most of the site prep work is already completed, but some additional steps will be necessary to ensure
good seed germination.
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These sites also present their own unique challenges, as they are often compacted and rocky, and are
typically stripped of the vegetation and topsoil prior to construction without the use of any herbicides
to control undesirable, non-native vegetation. Treatment with selective herbicides will be necessary
following installation and establishment to control these plants.
Photograph 3-5. Seeding can be done using a broadcast seeder for bare-earth sites
(Left: tractor mounted broadcast seeders can be used on large sites; Right: smaller hand-
held spreaders are ideal for small sites.)
Photograph 3-6. Sites seeded using
broadcast equipment should be followed
with a light cultipacker to ensure good
seed-to-soil contact.
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Table 3-7. Site Preparation and Planting Methods
Application: New Construction (Bare-Earth) Sites
Preparation Timeline: Begin planning in advance or in the early stages of a construction project
Total preparation time: 1 to 2 weeks (depending on site size)
Planting timeframe: Early spring or late fall (after hard frost)
Benefits: Relatively inexpensive and easy preparation.
Can be done with poorly cleaned seed stock.
Multiple equipment options for various project
sizes (ATV-mounted, tractor-mounted, and
hand-held broadcast seeders.)
Drawbacks: Requires a smooth, well-prepared seed bed.
Increased weed pressure from the seed bank
due to lack of pre-treatment.
Broadcast seeding equipment can be difficult
to calibrate and may not accommodate larger
seeds.
Installation Instructions: 1) Remove large stones/debris from the planting area to allow for easier mowing/maintenance once
established. If not already completed by the contractor, replace the topsoil layer and grade loosely.
2) If the soils are compacted and/or composed of heavy clay soils, use tilling equipment when the soils are
dry to rough-up the top 6 inches of soil to allow for good soil contact.
3) Broadcast the desired native seed mix, with an appropriate annual cover crop, such as common oats
(Avena sativa), using the vendor recommended seeding rate (in pounds of pure live seed per acre (PLS
LBS/AC)).
4) Prepared areas should be immediately seeded. If outside the recommended planting timeframe, install a
mix of temporary annual cover crop species (see Table 3.1) until the permanent mix can be installed.
5) Use broadcast seeding equipment with an internal agitator and a flow gate that can be closed enough to
create a slow, steady flow, allowing for even distribution of the smaller seeds. An inert carrier or bulking
agent can be used to provide more even distribution and provide a visual aid to the installer.
6) If the site is smaller than 2 acres, broadcast seeding can also be done by hand. If using this method,
divide the seed mix into two or more batches to ensure the seed is evenly distributed. Walk in parallel,
overlapping passes, using the larger seeds as a visual aid, and spread the remaining batch(es) in a
perpendicular direction.
7) Use a landscape-type roller or cultipacker to lightly press the seed into the soil bed. This ensures good
seed to soil contact and will improve germination. Do not till or cover the seed with soil.
8) Use high-quality, weed-free straw to apply a light mulch cover to the seeded area. This will help to retain
soil moisture and prevent runoff of the seed and loose soils.
A similar restoration method can be used to establish a high-diversity, showy planting site. The
process for this type of planting would include much more soil preparation, and is much more labor
intensive than broadcast seeding a bare site. If sod or other existing vegetation is present, the site
needs to be treated with an herbicide and tilled under; or the sod/vegetation can be stripped using a
sod-cutter or other equipment. Tilling the soils will bring up undesirable vegetation from the seed
bank, and thus will require multiple herbicide applications, and the use of temporary cover species.
This method is typically more costly due to the additional labor required for site preparation.
Table 3.8 outlines the procedures that should be used when establishing a showy planting site.
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Table 3-8. Site Preparation and Planting Methods for Sites in High-Profile Areas
Application: High-Profile Areas
Preparation Timeline: Total site preparation time: a minimum of 6 months
Planting timeframe: Early spring or late fall (after hard frost)
Benefits: Intensive soil preparation alleviates
compaction.
Provides a more landscaped appearance.
Drawbacks: Labor intensive process that can increase
costs.
Tilling soils will bring up many weeds, and
will require multiple herbicide treatments.
Installation Instructions (Seed): 1) If sod or other vegetative cover is present:
a) Apply a broadcast herbicide treatment, using glyphosate at the rate specified on the label for the
vegetation being treated, in early spring (beginning of the growing season) to kill the existing
vegetation and follow up with tilling the site under after the vegetation has died back.
b) Or, use a mechanical sod-cutter, or other equipment to directly remove the vegetative layer
within the site. This can be done with or without an initial herbicide application.
2) Following removal or tilling of the vegetation, broadcast seed a temporary cover crop, such as common
oats (Avena sativa). This will be necessary to stabilize the soil until the site can be treated with herbicide
again following germination of weed seeds.
3) In early to mid-summer, apply a selective, broadleaf herbicide (such as 2,4-D Amine) to the planting
area to control for weeds such as thistles.
4) Allow the site to grow through the fall season and re-evaluate the vegetation to determine if a third
herbicide application is needed. If the undesirable vegetation is controlled, mow the vegetation to less
than 6 to 8 inches and rake the thatch.
5) Broadcast the desired native seed mix using the vendor recommended seeding rate (in pounds of pure
live seed per acre (PLS LBS/AC)).
6) Use broadcast seeding equipment with an internal agitator and a flow gate that can be closed enough to
create a slow, steady flow, allowing for even distribution of the smaller seeds. An inert carrier or bulking
agent can be used to provide more even distribution and provide a visual aid to the installer.
7) If the site is smaller than 2 acres, broadcast seeding can also be done by hand. If using this method,
divide the seed mix into two or more batches to ensure the seed is evenly distributed. Walk in parallel,
overlapping passes, using the larger seeds as a visual aid, and then spread the remaining batch(es) in a
perpendicular direction.
8) Use a landscape-type roller or cultipacker to lightly press the seed into the soil bed. This ensures good
seed to soil contact and will improve germination. Do not till or cover the seed with soil.
9) Use high-quality, weed-free straw to apply a light mulch cover to the seeded area. This will help to retain
soil moisture and prevent runoff of the seed and loose soils.
If the desired outcome for a site is to have a more landscaped appearance, Step 1b (above) can be
used to create a planting bed by removing all vegetation. This area can then be built-up with topsoil
and planted with a variety of native plants, in plug or container form. The area can be mulched as
desired to create a clean, landscaped bed, as shown in photos 3-7. This method is much more costly
and labor intensive than typical seeding projects, and the resulting landscape bed requires more
maintenance to keep it weed-free, but it provides instant gratification and color for any high-profile
site.
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No-Till
In most cases, the appropriate method for preparing and installing a roadside pollinator habitat will
be through the use of a native no-till seed drill. There are two general types of seed drills available:
grain drills that have a single seed box, used for planting heavy grains such as oats and wheat; and
grassland seed drills that use multiple boxes designed for a variety of different seed types. Grain
drills are not suitable for planting native prairie seed mixes, as they contain a mixture of large/heavy,
fluffy, and smooth, small seeds.
Photograph 3-7. Native pollinator gardens were installed at the Middle Ridge and Vermilion Valley
Service Plazas in Amherst, Ohio in May 2016. This informational kiosk helps visitors identify 17 native
species planted at the sites.
Photograph 3-8. (Left) Native no-till seed drills should be used to install native wildflower mixes;
(Right) Grain drills are suitable for seeding sunflowers or other large seed.
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Grassland drills are available as traditional drills, which require
seedbed preparation, and as no-till drills that do not require any
soil preparation. These drills are generally equipped with three
separate seed boxes to ensure the appropriate amounts of each
seed type are evenly distributed. The first box is used for grains,
such as oats and ryegrass seeds, which are large and heavy
compared to other grasses and forbs. The second box contains
agitator wheels that help to mix and feed fluffy seeds or seed
with chaff, such as Andropogon gerardii (little bluestem) and
Sorghastrum nutans (indiangrass). The last box is used for
small grass, forb, and legume seeds, such as Panicum virgatum
(switchgrass), Coreopsis lanceolate (lanceleaf coreopsis), and
Chamaecrista fasciculate (partridge pea).
Proper drill calibration is critical to ensure that all seeds are applied evenly and at the desired rate.
The smooth, hard seeds will move through the feeder-tubes much more easily than fluffy seeds, and
will cause uneven distribution if the seed drill is not properly calibrated. Consult the manufacturer’s
guidelines for instructions on how to calibrate each seed drill prior to any seeding activities.
Complete a new calibration each time a new seed mix is used. Settings can be recorded for each
particular seed mix for future reference. Weather conditions such as temperature and humidity can
affect the calibration settings. Recheck the setting throughout the day to ensure feeder-tubes do not
become clogged, and that seed from all boxes is flowing properly, and is being installed at the proper
depth.
Most seed drills have an adjustable planting depth, typically ranging from ¼ inch to 1 inch in depth,
to accommodate different seed types. The coulters (disk openers) cut a furrow in the sod/soil and the
seed is dropped in behind via the feeder tubes. These are followed by a set of packer wheels that
press the soil back in over the seed. Most native grass and wildflower seeds have a recommended
planting depth of ¼ to ½ inch, making setting the correct depth a very important step in the
calibration process.
This method is most commonly used on
large sites that have existing herbaceous
vegetative cover, and is very effective in
establishing native seed with minimal soil
disturbance. This method also requires that
the site be prepared well in advance of when
the installation is anticipated, as it requires
multiple herbicide applications over the
course of a growing season to control for
undesirable vegetation. It is important to
reduce weed pressure prior to planting as
native warm-season plants grow much more
slowly than typical roadside vegetation,
spending the first two to four years laying
down their extensive root systems, and is easily outcompeted by existing cool-season grasses.
Table 3-9 provides a guide to installing native seed using this method.
Photograph 3-10. It is important to complete multiple broadcast
herbicide applications at a site prior to installing native seed to
control weed pressure.
Photograph 3-9. No-till native drills have
a fluffy seed box with agitator wheels to
mix and feed out fluffy seeds.
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Table 3-9. Native No-Till Drill Site Preparation and Planting Methods
Application: Large sites with existing vegetative cover, i.e., old fields, interchanges, etc.
Preparation Timeline:
Total site preparation time: a minimum of 6 months
Planting timeframe: Early spring or late fall (after hard frost)
Benefits:
No soil preparation is required, resulting in
minimal soil disturbance, and fewer weeds.
Easy use for planting large areas.
Specialized native seed drills have more accurate
calibration and depth controls to ensure proper
installation, and are equipped to handle small
and fluffy seeds found in native mixes.
A separate step for cultipacking is not required,
as the drill is equipped with packer wheels.
Drawbacks:
Native no-till seed drills are expensive to
purchase and not readily available in many areas.
Require careful calibration to ensure proper
seeding rates and depths.
Requires the use of a tractor and operator.
Requires clean seed. Native seed that is not well
cleaned can become clogged in the delivery
tubes.
Single Herbicide Application Site Preparation:
Timing: Spring
Use: This option can be used for sites with little
weed pressure, but should not be used for sites
where fescue or orchard grasses are the dominant
cover.
Procedure:
1) Mow vegetation to less than 5 inches in the
previous fall or winter, prior to spring green-up.
2) Apply broadcast herbicide application of
glyphosate product, per the product label, in
April/May, after vegetation has grown 4 to 6
inches.
Double Herbicide Application Site Preparation:
Timing: Fall and Spring
Use: This option should be used for all sites
where fescue or orchardgrass are the dominant
cover.
Procedure:
1) Mow vegetation to less than 5 inches in late
summer (August/September).
2) Apply broadcast herbicide application of
glyphosate product after vegetation has actively
grown 4 to 6 inches in September/October.
3) Apply a second application of glyphosate
product just prior to planting in April/May, after
the remaining vegetation grows 4 to 6 inches.
Seed Installation Instructions:
1) Plant only when soil is dry enough, as wet conditions can cause mud and seed to stick to the coulters, packer
wheels, and other components rather than being planted in the ground.
2) Keep seed separated by size/type until ready to plant, and loosely fill each seed box with the appropriate seed
type. If ordering a pre-mixed seed mix, ask the vendor to separate small, fluffy, and grain seeds into separate
bags. Alternately, the pre-mixed seed can be added to the fluffy seed box only, where the agitator wheels will
help to keep the small seed mixed in. The cover crop seed (i.e., oats or rye) can be added to the grain box
separately.
3) Adjust the planting depth to no more than 1.5 times the small seed diameter, which for most wildflower seed
mixes is no deeper than ¼ inch. Periodically check to see that the seed is being dispersed at the correct depth
and adjust as necessary.
4) Calibrate the seed drill per the manufacturer's instruction manual to ensure the mix is applied at the
appropriate seeding rate specified by the vendor.
5) Operate the drill at less than 5 mph to ensure seeds are sown evenly and the equipment is not damaged.
Periodically check the drill throughout the seed installation process to ensure the feeder tubes are flowing
freely, seed is being deposited in the furrows, and that the equipment is not damaged and functioning properly.
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Guide for Roadside Pollinator Habitat Establishment and Maintenance
Post Establishment Maintenance and Best Management Practices
Following the establishment of a pollinator habitat, proper site maintenance, especially in the first
three years, will ensure a successful project. This can be achieved through the use of the GIS
database of all established sites and their assigned management regimes, and implementing a
consistent mowing and weed management schedule that supports native plants and wildlife. It is also
important to know the site conditions, be able to identify the desirable and undesirable vegetation,
and know how to appropriately address issues with weed pressure, pests, and disease. Utilizing
mowing, trimming, and herbicide management techniques will enable you to maintain pollinator
habitat during the short-term establishment period, as well as over a long-term basis. By focusing
only on problem areas and using a targeted approach, ODOT can save time and money.
This section will review important aspects to keep in mind when managing pollinator habitat along
highway ROWs, including: utilizing mow-management at the appropriate times to avoid
unintentional negative impacts to plants and wildlife; appropriate use of herbicides to manage for
undesirable vegetation, including application methodology and herbicide recommendations; short-
term maintenance requirements during the establishment period; and long-term maintenance
practices.
Plant Life Cycles, Wildlife Nesting Seasons, and Mowing
Mowing is an important aspect of roadside vegetation
management, both for regular maintenance of highway ROWs, as
well as in IRVM practices. Mowing is used to maintain a safety-
zone or clear-zone along the shoulder and driver line-of-sight, as
well as to control woody vegetation, reduce potential wildfires,
and to control undesirable non-native vegetation. But done at the
wrong time of year, mowing can directly kill pollinators, as well
as impact their food and shelter resources, causing further
declines in local populations.
In Ohio, the growing season for native plants can extend from
April/May through September, depending on where in the state a
site is located and annual variations. Mowing during the growing
season results in negative impacts to pollinators and vegetation,
can directly affect pollinators by removing nectar producing plants and butterfly host plants, and can
reduce native plant growth.
Photograph 3-12. Mowing should be done
during the dormant season to avoid direct
impacts to pollinators.
Photograph 3-11. Native no-till seed drill are designed to plant sites with an
existing sod or thatch layer provided the vegetation is sprayed and mowed prior
to planting, and results in healthy establishments of native wildflowers.
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Mowing during the growing season can also directly kill ground nesting birds and pollinators that are
in the egg or larval stages, and destroy entire bee colonies.
For these reasons, mowing should be avoided during the growing season. To reduce harm to wildlife,
mow the project site only once per year, or every other year once established, during early spring or
late fall when the vegetation is dormant and no plants are actively flowering. To further reduce direct
wildlife casualties, mowing equipment can be equipped with a flushing bar to flush birds and other
wildlife from the area. Additionally, reducing mower speed and setting mowing decks heights high
can also be beneficial techniques to avoid wildlife casualties. However, it is difficult to avoid all
impacts to pollinators when mowing.
Noxious Weed Control: Utilizing Herbicides
Noxious weed control is critical to establish pollinator
habitat. The first three years after planting will require the
most weed control efforts. After the site has become
established with mature native plants, noxious weed control
efforts should decrease. Herbicides are one of the primary
tools that can be used to control noxious weeds, trees, and
shrubs. However, if used improperly, herbicides can
directly harm pollinators by removing nectar resources and
host plants.
Applicators should be trained on the proper use of
herbicides, including knowing the proper herbicide type, timing, and application method to use, as
well as in the proper use and calibration of application equipment. Applicators should also be trained
in basic vegetation ID. This is critical to ensure that herbicide applications are targeted at the correct
species, and to identify what type of herbicide to use at what time of year for the maximum
effectiveness. This can be achieved through training workshops, and providing maintenance staff and
contractors with pocket ID guides with photos and descriptions of the most common roadside weeds,
what herbicides are effective, and their life-cycles for proper treatment timing. Additionally, GPS
units are useful tools for locating problem areas and areas to avoid, tracking where weed populations
are present and what species are there, and then adding this information into the ODOT ROW GIS
Database.
Identify Problem Areas
The initial step in controlling undesirable vegetation is to identify the problem areas by conducting
an inventory of all project sites. This can be performed throughout the season as areas are managed,
or when other biological surveys are being performed. Updating information throughout the year will
keep records current and avoid lengthy survey periods. Mapping these areas with a GPS will also be
helpful for future treatments. Use these data to identify and prioritize sites that require treatment
based on the species and density present at each site, and establish the type of treatments needed.
Considerations:
Sites with aggressive weeds, such as reed canary grass (Phalaris arundinacea) or common
reed (Phragmites australis), or densities of undesirable vegetation greater than 50% should
be given highest priority for treatment.
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Do not disturb large areas of habitat at the same time Try to divide up large sites or rotate
multiple sites within the same area for treatment each year.
Continually update GIS data on undesirable species to plan management activities
appropriately each year.
Choosing the Appropriate Herbicide
There are a wide variety of herbicides available, and choosing the right one for each application is
important to ensure off-target effects to native plants, wildlife, and the environment are minimized.
Once the undesirable species and conditions of a site are identified, an appropriate herbicide should
be selected to control for these species. More than one type of herbicide may be necessary if there are
both broadleaf and grassy weeds present. Broad-spectrum herbicides and herbicides that move
through soils should be avoided in established pollinator habitats where possible.
Another consideration is whether the site requires a specific herbicide formulation based on the
presence of water or potential for herbicide runoff to enter waterways such as ponds, streams and
ditches. There are specific formulations of most herbicide types, for example, AquaNeat® and
Rodeo® are aquatic formulations of glyphosate. Appropriate adjuvants should also be selected for the
specific application. If there is a chance the herbicide can runoff into a nearby water source, an
aquatic formulation should be selected to prevent negative impacts on aquatic vegetation and
wildlife. Table 3-10 contains various herbicides available for roadside vegetation management and
their application. Figure 3-8 shows a flowchart to aid in deciding what herbicide is appropriate for
each application.
Table 3-10. Herbicides used for roadside management listed by trade name, active ingredient,
concentration (% for dry, lb/gal for liquids), primary application (pre-emergence or post-emergence),
and most common use along roadsides (TVC is total vegetation control).
Trade Name Active
Ingredients Concentration Application Common Use
AquaNeat glyphosate 4 lb./gal (5.4
lb./gal) POST nonselective
Habitat imazapyr 2 lb./gal POST nonselective
Edict IVM pyraflufen-ethyl 0.2 lb./gal POST broadleaf
Escort XP metsulfuron 60% POST broadleaf, brush
Garlon 3A triclopyr 3 lb./gal POST broadleaf, brush
Tahoe 4E triclopyr 4 lb./gal POST brush
Journey glyphosate
imazapic
1.5 lb./gal
0.75 lb./gal PRE, POST TVC
Karmex XP diuron 80% PRE TVC
Krenite S fosamine 4 lb./gal POST brush
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Table 3-10. Herbicides used for roadside management listed by trade name, active ingredient,
concentration (% for dry, lb/gal for liquids), primary application (pre-emergence or post-emergence),
and most common use along roadsides (TVC is total vegetation control). (Continued)
Trade Name Active
Ingredients Concentration Application Common Use
Krovar I bromacil
diuron
40%
40% PRE TVC
Milestone VM aminopyralid 2 lb./gal POST broadleaf
Oust Extra sulfometuron
metsulfuron
56%
15% PRE, POST TVC
Oust XP sulfometuron 75% PRE, POST TVC
Overdrive dicamba
diflufenzopyr
50%
20% POST broadleaf
Payload flumioxazin 51% PRE, POST TVC
Pendulum AquaCap pendimethalin 3.8 lb./gal PRE TVC
Sahara DG diuron
imazapyr
62%
8% PRE, POST TVC
Throttle XP
sulfentrazone
Sulfometuron
chlorsulfuron
48%
18%
9%
PRE, POST TVC
Tordon 101M 2,4-D
picloram
2.0 lb./gal
0.54 lb./gal POST broadleaf, brush
Tordon K picloram 2 lb./gal POST broadleaf, brush
Triplet SF
2,4-D
MCPP
dicamba
2.4 lb./gal
0.63 lb./gal
0.23 lb./gal
POST broadleaf
Vanquish dicamba 4 lb./gal POST broadleaf, brush
Velpar DF hexazinone 75% PRE, POST weeds in crown
vetch
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Figure 3-8. The type of herbicide selected should be based on the type of control desired. Use
selective herbicide where possible to avoid off-target impacts to desirable vegetation,
and use nonselective herbicide for site preparation to control all vegetation.
Choosing the Appropriate Application Method
There are different modes of application that can be used depending on the size, density, and goal of
the treatment. Once an herbicide type and formulation is selected for the site, an application method
should be chosen based on the density of the weeds present and the sensitivity of the surrounding
vegetation.
Non-Selective Application Methods
This type of application is used when the goal is to eliminate all the existing vegetation from a site.
Broadcast spraying is a common method used for this application. Broadcast applications involve
applying a uniform spray over the entire treatment area, and can be used to effectively treat an area
that is dominated with noxious weeds. This method can also be used with selective herbicides, such
as an aminopyralid, to treat select weeds. When applied according to the product label and using
proper equipment operation, this method can be safe for use on non-target plants. Broadcast
herbicide applications can be made with a few different types of equipment.
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Boom Sprayers
Boom sprayers are one of the most common tools used in
large broadcast applications, such as roadsides, and are
available for a variety of different equipment types, including
ATVs, tractors, aircraft, and vehicles. Herbicides are applied
uniformly across a site using several, calibrated spray nozzles
mounted in a row. A disadvantage of boom sprayer
equipment is that it does not work well on steep or rough
terrain that cannot be traversed with ground equipment, and
aircraft-mounted booms are limited to relatively large areas
due to maneuverability and cost restraints.
Gun Sprayers
Gun sprayers are another common tool for broadcast
applications that can be used in smaller areas, such as
along fencerows, ditches, and other roadside features,
where boom sprayers cannot gain access.
Spray guns use a single calibrated nozzle and can spray
distances of 10 feet or more, depending on the type used.
They can be mounted to tractors, vehicles, and ATVs, and
are usually mounted with a hose and reel, allowing the
applicator the flexibility to spray from the vehicle and to
walk out to treat smaller patches of weeds. There are a few
disadvantages to this equipment as well. Gun sprayers do
not allow applicators to easily make uniform applications
and can cause applicators to miss weeds, especially those hidden under other vegetation. This method
also results in a higher application rate per acre than boom sprayers.
Selective Application Methods
Selective application methods are used to target specific plants, leaving desirable plants unharmed, in
areas with higher densities of native, desirable vegetation. Selective spraying involves the use of
small, targeted equipment such as backpack sprayers, handheld sprayers, and wick applicators. This
method allows for the use of less selective herbicides, such as glyphosate, when used with well-
trained applicators under appropriate conditions. This method is also highly effective with selective
herbicides as well. There are various types of equipment for this method as well.
Spot-spraying
Spot-spraying to control undesirable vegetation is effective
and should be performed with caution so that desirable
plants are not sprayed, especially when using non-selective
herbicides. Spot-spraying can be performed with a
backpack or handheld sprayer. Proper spot-spraying
techniques can help to minimize drift. Avoid spraying
during high winds to prevent drifting to desirable plants and
neighboring properties and avoid broadcast spraying
because it can destroy pollinator host plants, nectar
producing plants and can drift to adjacent properties.
Photograph 3-13. Boom sprayers can be
versatile and used with ATVs for smaller
sites.
Photograph 3-14. Gun sprayers are useful for
treating vegetation in hard to reach areas, such
as roadside ditches.
Photograph 3-15. Backpack sprayers can be
used to selectively treat undesirable vegetation
in pollinator habitats.
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Wicking
Wicking (wipe-on) applications can be used in areas where
noxious weeds are encroaching in areas where pollinator plants
are well established, or where sensitive, threatened, or
endangered plants exist. Herbicides are applied using a sponge,
or other absorbent material, that draws herbicide up through
wicking action, and can be wiped directly onto the leaves and
stem of the targeted plant, avoiding overspray and drift entirely.
Wick applicators are generally small, handheld devices, but can
be large; tractor or ATV mounted wicking bars that can be used
over larger areas with taller, non-native vegetation over
desirable understory plants. This method uses higher herbicide
concentrations (10% to 100%) than the other methods listed, and
should be carefully applied and transported through habitats and
areas with waterways to avoid spills. This method is very time-
consuming compared to other methods, and is only effective
over small areas.
Drift Management
A major concern of herbicide application is the management of drift. Herbicide drift can impact
nearby crops, harm wildlife, contaminate water supplies, and deposit residues on edible crops,
especially organic grown crops that are located close to the treatment areas. It is important to take
necessary steps and precautions to minimize off-target impacts.
There are two types of drift:
Vapor drift is a function of the herbicide formulation and air temperature.
Particle drift is a function of the application method and equipment.
Vapor Drift Control:
1. Always follow the product label for herbicide concentration, application methods, and
weather restrictions.
2. Avoid using the fine spray setting on the nozzle.
3. Do not spray when temperatures exceed those listed on the product label or during high
winds in excess of 10 mph. If an herbicide is applied during either time using the fine setting
on the nozzle, it can cause herbicide particles to travel long distances. On a calm day with
cool temperatures it takes only seconds for the herbicide particle to evaporate.
Particle Drift Control:
1. Control the pressure by setting the nozzle to produce coarse droplets and do not increase the
pressure to provide higher outputs, instead increase the nozzle size to increase the spray
volume/acre and continue to keep it set at the recommended pressure.
2. Avoid spraying during high winds. Some herbicides will indicate on the label a specific wind
speed. In general, spray when winds are less than 10 mph.
3. Spray when the wind direction is blowing away from areas you want to avoid.
4. Use a drift control agent when possible, which use thickening agents such as polyacrylamide
or polyvinyl polymers to increase droplet size. (i.e. Mist Control, Crosshair, or Bull’s-Eye)
Photograph 3-16. Wicking bars can be
attached to ATVs to selectively treat taller
weeds.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-38
Guide for Roadside Pollinator Habitat Establishment and Maintenance
Short-Term Maintenance during Establishment
Weed control is critical during the first three years after planting. Less maintenance will be required
once the pollinator plants have become established and native plants dominate the site. Knowing
plant life cycles will aid the timing of management activities. Weed management during this
establishment period can be achieved by mowing and herbicide applications when necessary.
Generally, mowing on the highest setting can be used to top clip undesirable vegetation, since most
native grasses and forbs remain fairly short during their first year, mainly putting energy into root
development.
Care should be taken to identify weeds before removal to determine the most applicable approach
and ensure the correct species are being targeted. Some naturally occurring native and naturalized
plants can provide pollinator resources during establishment, and are not generally aggressive or
weedy. Herbicides should be reserved for noxious weeds that are invading establishing pollinator
habitats and have the potential to outcompete the desired species.
Weed Control Options:
Mowing/String-trimming: Either method can be used in problems areas where noxious
weeds are abundant. Mowing or trimming can be performed multiple times during the first
three years after planting to help control noxious weeds. Subsequent mowing activities
should only be performed during early spring or late fall to avoid wildlife nesting seasons and
plant bloom periods.
String-trimming can be performed throughout the year in areas where a mower cannot get
access to control noxious weeds, or as a targeted weed control approach. If trimming is
performed during the plant blooming season, be careful not to cut down more than 30-50% of
the desirable plants at any one time.
Spot-spraying: Spot-spraying to control undesirable vegetation is effective and should be
performed with caution so that desirable plants do not get sprayed. Spot-spraying can be
performed with a backpack, handheld sprayer, or wicking bar. Applicators should be able to
identify the plants that need to be treated as well as plants to avoid. Spot-spraying records
should be kept and assessed. This can be done by using a GPS to collect data of areas that
have been treated and areas to avoid.
Using the above techniques, the following management strategies should be followed to control
weeds during the first three years of stand establishment:
Year 1 (Planting Year)
Scout sites between May and June to identify problems such as emerging noxious weeds or
trees. These areas may need treatment to control.
During the first growing season it is important to keep weeds from maturing by mowing at a
height of six inches before weed seed production starts (usually June/July). *Note: It is
important to clean off the mower prior to mowing to avoid the spread of noxious weed seeds.
Cut weeds down before they get taller than 16 inches, and do not allow them to exceed 18
inches or form seed heads. *Note: Large amounts of cut vegetation can bury the pollinator
plantings, so it is important to mow before the vegetation gets too high and the biomass will
form a thatch layer when mowed.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-39
Guide for Roadside Pollinator Habitat Establishment and Maintenance
A second mowing will be required before fall. Some of the native plants will get mowed
down during the second mowing but this is part of the management requirements, and will
not set back growth. *Remember: Native plants are putting their energy into developing
their root systems at this time.
Year 2
Inspect pollinator sites in early spring for undesirable vegetation dominating more than 30%
of the stand. Mow these areas very short (4-6 inches) until the native forbs start to green up.
Continue to mow throughout the season as needed, at a height just above the native seedlings
to prevent undesirable vegetation from dominating the site. *Note: Avoid mowing more than
50% of a site at any given point to avoid removing all food and shelter resources for
pollinators.
Continue to monitor the sites throughout the second year.
Years 3 & 4:
By the third or fourth year, the pollinator habitat should be well established and will not
require as much maintenance, but will need some disturbance, such as mowing or burning, to
encourage native plant growth and remove undesirable species.
Repeat steps for Year 2 if weeds are persistent, and/or spot-spray noxious weeds where
necessary.
Continue to monitor the sites throughout the year.
Additional Plantings
During the first three years it is important to monitor the project areas for plant success. Some areas
may require additional plantings or seeding. These areas should be re-seeded during the next seeding
period. It will be important to assess the likely cause of the failure to determine if the species selected
were not appropriate for the area(s) that did not establish, if weed pressure prevented establishment,
or if another factor was at play. Once this is determined, make any necessary adjustments to the seed
mix and/or management regime and make preparations for supplemental seeding if needed.
First, if using an equipment-mounted or handheld broadcast seeder, mix all seed with a
carrier and cover crop as needed (please refer to the Site Preparation and Planting Methods
section for planting details). This will aid in even distribution of the seed mixture. For small
areas where seed did not germinate, hand broadcasting additional seed can be easily done.
Broadcast the seed mixture in the problem areas.
To ensure good seed to soil contact, firm the seeded area by tamping down the seed using a
roller, hand tamper, tractor or vehicle.
Lastly, mulch newly seeded areas that are bare soil (have no vegetative layer) to prevent
erosion and to retain soil moisture.
Watering after planting is not necessary. The seeds will germinate but at a slower rate.
Long-Term Maintenance Post-Establishment
Following the establishment period, pollinator plantings should be managed long term to maintain an
open and early successional habitat. Management techniques such as mowing, burning, or haying can
be used to achieve this.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-40
Guide for Roadside Pollinator Habitat Establishment and Maintenance
Vegetation Control Methods
There are several methods that can be used to manage a pollinator habitat for weeds and biomass to
ensure the stand remains healthy. The following are some of the most commonly accepted methods
that can be used to manage roadside pollinator habitat.
Mowing
Mowing is an effective method to control weeds and to remove old growth from a roadside pollinator
habitat. Once a site has become established, mowing frequency should be reduced to once per year or
every other year in areas beyond the clear-zone (safety-zone), to provide the greatest benefit to
pollinators. Do not mow more than twice in a year once a stand has become established as this can
harm the plants and wildlife. Mowing height should always be raised to six inches or higher and a
flushing bar can be used to avoid direct impacts to pollinators and other wildlife. Mowing should not
occur during the primary wildlife reproductive period of March 1 thru July 15.
Timing: Mowing should only be performed during winter, early spring, or late fall.
Applications: Mowing can be used for weed management and to remove old vegetative
growth.
o To control weeds, mow to a height of 6 inches in early spring to knock-back cool-
season grasses and weeds. Mowing can be repeated in June or July if a mowing
height greater than the desirable vegetation can be achieved. Again, do not mow more than 50% of a site at any one time to leave a refuge for pollinators and other wildlife.
o To remove thatch, mow to a height of 6 inches in late winter or early spring, while
the vegetation is still dormant or just beginning to flush. Use a landscape rake or
other implement to remove cut debris from the planting areas. Mowing for this reason
should only be done once every two to three years, on a rotating cycle between all
sites.
Prescribed Burning
Prescribed burning is the ideal method used to suppress woody
plant encroachment and to manage thatch that can accumulate
over time. It also offers the following benefits:
Stimulates the growth of many native prairie plants,
including warm-season grasses
Recycles nutrients
Warms the soil and gives warm-season plants an earlier
start
If burning is an option, it should only be performed on small
sections and no more than every 3 to 5 years during the early spring or fall, depending on the goals of
the burn. This will promote floral diversity and minimize impacts to pollinators. Burning can
negatively impact pollinators and cause long-term impacts to certain pollinator species populations if
performed during the wrong time of the year. Before prescribed burning can take place, staff must be
properly trained, a burn plan must be developed, and the appropriate permits must be obtained.
Timing: Burning should only be performed during early spring (February, March, and April) or fall.
Photograph 3-17. Prescribed burning
helps to control undesirable weeds, and
promotes warm season grasses.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-41
Guide for Roadside Pollinator Habitat Establishment and Maintenance
Applications: Burning can be used for limited weed management and to remove
accumulated thatch on a site.
Evaluating Pollinator Habitat Success
There are two major components to the success of any pollinator habitat or
pollinator focused IRVM program: vegetation and pollinators. Both of these
aspects need to be evaluated to ensure each project’s success. There are a
wide variety of methods for assessing these components, using a plethora of
different factors and variables. No one way is correct, but the appropriate
data and collection method must be selected for each to accurately assess
the diversity changes at each site. It is important to establish an evaluation
process for pollinator habitats in order to gauge how well a site is
performing and determine:
How well a seed mix performed, and what species are thriving
versus those that are not present at all.
What management practices are working well, and if adjustments
need to be made.
What noxious weeds are persistent and need targeted control.
If there are adequate floral resources available throughout the year
for pollinators.
What pollinators are utilizing a site, and what is their overall
abundance?
These factors should be assessed for each site prior to establishing a pollinator habitat and/or IRVM
program, as well as during and after site establishment. Tracking this data over time will help provide
information on ways to improve practices, which will save money over the long-term. These
assessments can be completed by trained ODOT staff members, or by university researchers, citizen
science groups, or other volunteer groups with plant and pollinator identification knowledge.
Evaluating Plant Species Abundance and Diversity
Evaluation of the plant species diversity and abundance within a roadside pollinator habitat should
ideally be performed prior to any site improvements to evaluate the baseline conditions. This will
help to provide information on what site preparation is necessary and what plant species should be
selected based on site conditions. This baseline evaluation also provides the data needed to compare
post-establishment results and determine if the site has truly been improved for pollinators.
When evaluating pre-establishment conditions, consider:
What is the dominant vegetation type? Grasses, forbs, or woody plants?
Are these primarily native or non-native species?
Are there any noxious weeds or invasive species?
How many total individual species are present, and in what quantity?
These are the simplest factors to consider, and should provide a basic comparison/progression of
each site to determine overall success.
Photograph 3-18. It is
important to evaluate the
vegetation to determine
the success of a pollinator
habitat establishment.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-42
Guide for Roadside Pollinator Habitat Establishment and Maintenance
Survey Timing: While it is ideal to survey a site multiple times each year (spring, summer, and fall),
staff availability and budget constraints may restrict the number of assessments that can realistically
be completed. Most native prairie plants flower in mid- to late-summer, making identification much
easier. If only one visit can be completed each year, be sure that the assessments occur within the
same period of time (i.e. mid-summer). This allows for direct comparisons between years, and plots.
Recommended Method: The most simplistic way to measure vegetation diversity is to assess the
percent cover of each species present, and compare the species found to the list of species included in
the seed mix. Using square meter quadrats can help define survey areas, but are not necessary. The
number of sampling points per site is dependent on the total size of the site, the number of unique
vegetation areas present, and the metrics being evaluated. As a general rule of thumb, use a minimum
of three of sample points per site, but enough points should be added to ensure that all vegetation
communities are accounted for.
Tools:
Evaluation form, clipboard, and writing utensil
Handheld GPS unit (with project boundary loaded)
Camera
Vegetation identification reference materials
Square meter quadrat (one with grid lines is especially useful for determining percent cover)
Plastic bags (for collecting vouchers for later identification)
General Process:
1) Determine the number of unique vegetation communities and the total number of sample
points required for each pollinator site.
2) Mark the location of each plot with a GPS unit so that the same plot can be assessed over
time.
3) Throw the quadrat into a representative area of the site and lay the square flat on the ground
(pull back tall vegetation to allow contact at or near the ground).
4) Work in sections and record all the plant species that are rooted within the quadrat
(remember to look under taller vegetation to ensure small seedlings are not being
overlooked).
5) Identify the plants to the lowest level practical (genus and species level is preferred).
6) Once all plant species have been recorded, assign a percent-cover to each species for the
quadrat (this is where grid lines are useful).
Once data is collected, it should be compiled into an electronic database along with any photos or
GIS data that were collected. An example assessment form has been included in section five for
reference, but a custom form can be developed to include other metrics as desired.
Evaluating Invertebrate Species Abundance and Diversity
Observing and documenting pollinator diversity and abundance is a critical aspect in determining the
success of pollinator habitat. As with vegetation surveys, there are many different methods and
metrics used to assess pollinator populations. Again, choose the method and data that best suits the
goals for assessing the project.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-43
Guide for Roadside Pollinator Habitat Establishment and Maintenance
Also, as noted in the previous section, it is important to assess the baseline conditions for each
proposed pollinator habitat, to determine if the establishment of native species has benefited.
When evaluating pre-establishment conditions, consider:
What plant species are in bloom at the time of the survey?
How many different types of pollinators are present, and in what quantity?
Are there primarily native bees, honey bees, butterflies, or other types?
What species of plants are they utilizing?
Identifying bees and other pollinator can be challenging, especially to the untrained eye. Working
with someone who is experienced in insect identification is the best way to ensure accurate data
collection. There are a number of pocket identification guides for bees and butterflies in Ohio,
including a simple bee guide of common Ohio bees from The Ohio State University, and an Ohio
butterflies and skippers guide from Ohio Division of Wildlife.
There are also other variables to take into account when surveying pollinators. It is important to note
weather conditions when making observations, as bees and many butterflies do not like temperatures
below 55°F, windy conditions, or overcast skies, and are relatively inactive in the morning and
evening hours. Most butterflies are active during the hottest part of the day, on days with low wind
and high humidity levels.
The most common methods for assessing insect populations require capture-kill techniques. There
are a variety of active and passive capture methods that can be used. Sweep netting is an active
technique, and is a relatively easy way to quickly collect a large variety of insects during a single
visit. Window-pane traps are a passive method of collection using a clear window and funnel to try to
force insects down into an ethyl acetate solution. There are also a variety of observational methods
that do not require the capture of insects, one of which is recommended here.
Survey Timing: April - October/Early November (ends after first hard frost). Again it is ideal to
complete surveys multiple times each year to capture all of the different species that are utilizing the
site; however, if only one or two visits can be made each year, choose the same period of time such
as late-summer, to compare data between years and sites.
Recommended Methods: Identifying insects during flight can be very difficult, and requires
excellent identification skills, and handling live bees can also be challenging. A simple method to
obtain basic pollinator population data, is to observe the number of pollinators that visit each species
of flowering plant for a set period of time. Pollinator species should be identified to the lowest
taxonomic level the surveyor is comfortable with.
Tools:
Evaluation form, clipboard, and writing utensil
Handheld GPS unit (with project boundary loaded)
Tally counter
Insect identification reference materials
Insect nets, traps, or other materials for capture (if ID is needed)
Plastic bags (for collecting vouchers for later identification)
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-44
Guide for Roadside Pollinator Habitat Establishment and Maintenance
General Process:
1) Initial Observations: Describe site age, general habitat description (trees, distance to water,
surrounding land use, nesting resources, etc.). Document which flowers are in bloom and
those that have yet to bloom (reference the list of species from the seed mix used.)
2) Only observe and identify insects visiting the reproductive parts of the flower. Do not count
pollinators sitting on petals, leaves, stems, or ones flying around the area.
3) Identify pollinators to the lowest taxonomic practical.
Table 3-11.
Ways to Differentiate Between Bee Species
If you do not know the differences between species, taking general notes on body composition can help make the
identification process easier when you return to the office.
1.) What is the size of the bee?
Large (¾ inch or greater)
Medium (½ to ¾ inch)
Small (¼ to ½ inch)
Very Small (less than ¼ inch)
2.) What is the shape of the bee?
Broad, rounded body
Long, narrow body
3.) What colors are present? (Exoskeleton and hairs)
Metallic or non-metallic
Hair color versus body color
Primary color of the head, thorax, and abdomen
4.) What is the distribution of hair?
Thorax and abdomen thickly covered
Thorax thickly covered, abdomen sparse or in bands
Body appears nearly hairless
5.) What is the location of scopa - densely arranged, highly branched hairs, used as a pollen basket
Hind legs
Underside of the abdomen
Not present
Bees:
Usually very hairy
Four wings
Long, elbowed
antennae
Broad, hairy legs
Often loaded with
pollen on scopa
Wasps:
Little or no hair
Four wings
Long antennae, not
elbowed
Legs narrow, not hairy
Little or no pollen (no
scopa)
Flies:
Usually little or no hair
Two wings
Short, thick antennae
Legs narrow, not hairy
Little or no pollen (no
scopa)
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 3-45
Guide for Roadside Pollinator Habitat Establishment and Maintenance
Literature Cited
DiTomaso, Joseph M. 1997. Risk analysis of various weed control methods. Proc. Calif. Exotic
Pest Plant Counc. Symp. Vol. 3.
Kremen, Claire, Robbin W. Thorp, and Neal M. Williams. 2002. Crop pollination from native
bees at risk from agricultural intensification. Proceedings of the National Academy of
Sciences 99.26.16812-16.
Kremen, Claire, et al. 2004. The area requirements of an ecosystem service: crop pollination by
native bee communities in California. Ecology letters 7.11. 1109-19.
Moroń, Dawid, et al. 2012. Abundance and diversity of wild bees along gradients of heavy metal
pollution. Journal of Applied Ecology 49.1. 118-25.
Moroń, D., H. Szentgyo¨rgyi, I. Grzes´, M. Wantuch, E. Rozej, R. Laskowski &
M. Woyciechowski. 2010. The effect of heavy metal pollution on development of wild
bees. Atlas of Biodiversity Risks – From Europe to the Globe, From Stories to Maps (eds
J. Settele, L.D. Penev, T.A. Georgiev, R. Grabaum, V. Grobelnik, V. Hammen et al.),
224–25. Pensoft, Sofia & Moscow.
Morandin, Lora A., and Mark L. Winston. 2006. Pollinators provide economic incentive to
preserve natural land in agroecosystems. Agriculture, Ecosystems & Environment 116.3.
289-92.
Perugini, Monia, et al. 2011. Heavy metal (Hg, Cr, Cd, and Pb) contamination in urban areas and
wildlife reserves: honeybees as bioindicators. Biological trace element research 140.2.
170-76.
Proctor, Michael, Andrew Lack, and Peter Yeo. 1996. The natural history of pollination.
HarperCollins Publishers.
Santamour, F.S. 1990. Trees for urban planting: Diversity, uniformity, and common sense.
Proceedings of the 7th Conference of the Metropolitan Tree Improvement Alliance.
7:57–65.
Spellerberg, I. A. N. 1998. Ecological effects of roads and traffic: a literature review. Global
Ecology and Biogeography 7.5. 317-33.
Trombulak, Stephen C., and Christopher A. Frissell. 2000. Review of ecological effects of roads
on terrestrial and aquatic communities. Conservation biology 14.1. 18-30.
United States Department of Agriculture. April 2009. National Agricultural Statistics Service.
United States Department of Agriculture. Natural Resources Conservation Service.
Pollinator Biology and Habitat.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 4-1
Frequently Asked Questions about Roadsides as Habitat for Pollinators
Ohio Department of Transportation
Statewide Roadside Pollinator Habitat Program
June 2016
Frequently Asked Questions about Roadsides as
Habitat for Pollinators
Table of Contents
Why is ODOT involved?
Wildlife Concerns
Financial/Cost Considerations
Safety Concerns
Adjacent Property Concerns
Pollinator Habitat Concerns
Native Plant Concerns
© Marty Nevils Davis | martydavisphotos.com
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 4-2
Frequently Asked Questions about Roadsides as Habitat for Pollinators
Table of Contents
Why is ODOT involved
1. Why is ODOT involved in plant pollinator habitat?
2. What is a pollinator?
3. Why do we care about pollinators?
Wildlife Concerns
4. How can roadsides be useful to pollinators?
5. How can pollinator habitat benefit other wildlife?
6. Will these efforts help with Colony Collapse Disorder?
Financial/Cost Concerns
7. Isn’t planting and maintaining a pollinator site a costly activity?
Safety Concerns
8. If roadsides are mowed less frequently, will this impact driver safety, especially collisions
with deer?
9. If the amount of wildflowers on roadsides increases, will the number of pollinators killed on
roads increase too?
10. Are collisions with vehicles a major source of mortality for pollinators?
11. If we have more bees, won’t we have more people getting stung?
Adjacent Property Concerns
12. Will any of the wildflowers planted on roadsides spread to my property and become weeds?
13. Are milkweeds present in the roadside a threat to livestock on adjacent land?
14. What are some adjacent land uses that benefit pollinators?
Pollinator Habitat Concerns
15. What is the minimum habitat size that would benefit pollinators along a highway right-of-way?
16. Is there a safe time to mow pollinator habitats that will be less harmful to pollinators?
Native Plant Concerns
17. Will local genotypes be used for planting pollinator habitat?
18. Why is it important to use native seed and local ecotypes when establishing pollinator habitat?
19. What should I do if I can't find an appropriate source for native, local ecotypes of seed for my
pollinator habitat?
20. Why use native plants, if they are more expensive than nonnative species?
21. Are there plants that can be harmful to monarchs?
22. What are some native plant species that I can plant in my garden to help pollinators?
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 4-3
Frequently Asked Questions about Roadsides as Habitat for Pollinators
1. Why is ODOT involved in plant pollinator habitat?
a. In 2015, the White House released its national strategy to promote the health of
honey bees and other pollinators in the U.S. The strategy calls upon all federal
agencies to develop their own plans to protect pollinators. In response to this
directive, U.S. Department of Transportation (USDOT) developed its own pollinator
protection plan that seeks to enhance pollinator habitat on Department facilities and
lands, increase pollinator habitat along roadways, work with State Departments of
Transportation to promote pollinator-friendly practices and corridors, and identify
opportunities to educate privately owned railways, pipelines, and other
transportation-related facilities about the need to increase pollinator habitat.
b. The HR 2738 Highways Bettering the Economy and Environment Pollinator
Protection Act (Highway BEE Act) authorizes the expenditure of funds for the
establishment of pollinator habitat for bees, birds, bats, and butterflies within the
right-of-way of federal-aid highway projects.
2. What is a pollinator?
Pollinators are animals (insects, birds, and mammals) that carry pollen between
flowers of the same species. The pollen then can fertilize the plant creating fruit or
seed. Bees are primary pollinators but there are several other species such as
butterflies, moths, beetles, flies, birds, and bats.
3. Why do we care about pollinators?
Pollinators play a significant role in the production of food crops as well as the
survival and reproduction of many native plants. Without pollinators many plants
could not set seed and reproduce; and without plants to provide pollen and nectar,
many animal populations would decline.
It is estimated that 85% of the world's flowering plants depend on pollination. This
includes more than two-thirds, or one-in-three mouthfuls, of our agricultural crops,
including many fruits, vegetables, nuts, and even livestock feed.
Insect pollination services are valued at as much as $27 billion each year in the U.S.
The declining pollinator populations are highly concerning, as they are a direct threat
to the agricultural industry and world food supplies.
(Sources: Klein et al. 2006; Losey and Vaughan 2006; Morse and Calderone 2000;
Ollerton et al. 2011)
4. How can roadsides be useful to pollinators?
Roadside areas can provide several ecological functions for pollinators, including
serving as foraging habitat, providing breeding or nesting opportunities, and helping
pollinators to move through landscapes by linking fragmented habitats. Not all
roadside areas are equally beneficial to pollinators. Areas with abundant wildflowers,
predominately native plants, managed by judicious mowing, herbicides, and other
management tools, provide the best roadside habitat. Although roadsides are not a
substitute for wildlife habitat, as patches of refuge for pollinators in otherwise
inhospitable landscapes, roadsides can contribute to the maintenance of healthy
ecosystems and the provision of ecological services such as crop pollination.
(Sources: Dirig and Cryan 1991; Hopwood 2008; Munguira and Thomas 1992; Ries
et al. 2001; Saarinen et al. 2005; Schaffers et al. 2012)
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 4-4
Frequently Asked Questions about Roadsides as Habitat for Pollinators
5. How can pollinator habitat benefit other wildlife?
Roadsides can support a variety of wildlife including small mammals and birds.
Long-distance migratory birds such as the ruby-throated hummingbird can use
roadside pollinator habitat as pit stops for resting and feeding.
Ground-nesting birds like meadowlark, grasshopper sparrows, bobolinks, killdeer,
ring-necked pheasants, and several duck species will lay their eggs and raise their
young in ditch bottoms and on back slopes of roadsides. In addition, small mammals
like rabbits, moles, voles, shrews, and mice will reside within the habitat areas.
6. Will these efforts help with Colony Collapse Disorder?
While not fully understood, Colony Collapse Disorder, defined as “a dead colony
with no adult bees and with no dead bee bodies but with a live queen, and usually
honey and immature bees still present,” is thought to result from a combination of
factors. Worldwide pollinator declines are attributed to the loss, degradation, and
fragmentation of habitat, introduced species, the use of pesticides, habitat disruption
from grazing, mowing, and fire, diseases and parasites, climate change, and other
environmental factors.
Managing existing habitat for pollinators and restoring additional habitat has been
demonstrated to increase pollinator abundance and diversity, and roadsides are a
widely available resource that provide an opportunity to increase pollinator habitat.
Roadsides can provide several ecological functions for pollinators, including serving
as foraging habitat, providing breeding or nesting opportunities, and aiding dispersal
of pollinators by linking fragmented habitats. Providing these food and nesting
resources for pollinators helps to keep populations healthy and better able to resist
threats such as parasites and chemicals that can lead to Colony Collapse Disorder.
(Sources: Altizer and Oberhauser 1999; Colla et al. 2006; Fiedler et al. 2012; Hatfield
and LeBuhn 2007; Johst et al. 2006; Kevan 1975; Kissinger et al. 2011; Klein et al.
2012; Kremen et al. 2002; Memmott and Wasser 2002; Morandin and Kremen 2013;
Pisa et al. 2015; Potts et al. 2010; Potts et al. 2005; Tallamy and Shropshire 2009;
USDA Agricultural Research Service, 2016)
7. Isn’t planting and maintaining a pollinator site a costly activity?
Although the establishment of native vegetation can take time and the initial costs
may be higher, maintaining native plantings is more cost-effective in the long term,
as opposed to maintaining traditional roadside habitats dominated by grasses.
Once established, native plantings persist over time and require less mowing,
herbicides, and other weed control measures, decreasing long-term maintenance
efforts and cost. In contrast, controlling the growth and spread of invasive plants
along roadsides through repeated mowing and rigorous herbicide use is very
expensive. The Florida Department of Transportation estimates an annual cost of
$33.3 million to maintain traditional state ROWs. Maintenance costs were estimated
to be reduced by at least 30% through the implementation of more sustainable natural
habitat management practices.
Further cost savings can be gained through other functions of native roadside habitat
such as pollination services, reduced stormwater flow, carbon sequestration, invasive
vegetation resistance, and aesthetics.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 4-5
Frequently Asked Questions about Roadsides as Habitat for Pollinators
Decreased mowing strategies save the taxpayer money that can go directly into future
roadway and bridge maintenance projects.
(Sources: Harper-Lore et al. 2014; Harrison 2014; O’Dell et al. 2007; Westbrooks
1998)
8. If roadsides are mowed less frequently, will this impact driver safety, especially
collisions with deer?
Frequency of mowing of the entire roadside doesn’t appear to influence rates of
deer/vehicle crashes. In fact, deer may actually prefer some roadsides that are mowed
more frequently because mowing can increase the palatability of some plants.
A strip of vegetation adjacent to the pavement that is mown regularly, while letting
the rest of the roadside grow to a reasonable height, can help to maintain visibility of
drivers and prevent deer/vehicle crashes.
(Sources: Barnum and Alt 2013; Guyton et al. 2014; Mastro et al. 2008)
9. If the amount of wildflowers on roadsides increases, will the number of pollinators
killed on roads increase too?
Although pollinators and other wildlife are going to be killed by vehicles as long as
we have roads, there are ways to reduce pollinator road mortality. Reducing roadside
mowing can reduce butterfly mortality, as can enhancing the diversity and abundance
of wildflowers on roadsides.
Current research suggests that, rather than luring pollinators to death-by-vehicle,
roadsides with high-quality habitat actually reduce pollinator mortality by providing
resources and reducing the need for pollinators to cross roadways in search of food
and shelter.
(Sources: Munguira and Thomas 1992; Ries et al. 2001; Skórka et al. 2013.)
10. Are collisions with vehicles a major source of mortality for pollinators?
Hundreds of thousands of pollinators are killed by vehicles on roads, but, research
suggests that the numbers are a small proportion of overall populations. Mortality
rates of butterflies on roads, for example, range from 0.6% to a maximum of 10% of
the population, depending on the species.
Roadside mortality can be higher for some species of pollinators than others. For
example, butterflies appear to be one of the more common groups of insects killed by
cars. Some butterflies that are strong fliers have the ability to dodge vehicles, while
other less adroit species are more susceptible.
(Sources: Girish 2007; McKenna et al. 2001; Munguira and Thomas 1992; Munoz et
al. 2015; Rao and Zielin et al. 2010; Ries et al. 2001; Skórka et al. 2013)
11. If we have more bees, won’t we have more people getting stung?
Many people are fearful of insects such as bees because they can deliver a painful
sting, but remember not all bees have a stinger and those that do typically use it as a
last resort, as it can be deadly for the bee.
Bees have developed their stingers as a defense against predators and intruders to
their hive, and generally only attack when they feel their colony is under threat. A
lone bee out searching for nectar or pollen away from their hive usually will not sting,
as they are primarily focused on gathering food.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 4-6
Frequently Asked Questions about Roadsides as Habitat for Pollinators
However, a bee may sting if it is handled roughly (swatted at or stepped on), gets
entangled in your clothing, or feels threatened in any way. Generally, if you leave a
bee alone, it will leave you alone.
(Source: Greene et al. 2005.)
12. Will any of the wildflowers planted on roadsides spread to my property and become
weeds?
While native plants do produce seed that can allow some species to spread beyond the
areas they were planted in, these plants are less likely to encroach on properties
adjacent to roadsides and become problematic weeds than many introduced plants. If
you do not change your current landscaping practices, then the spread of wildflowers
should not be an issue.
(Source: Harper-Lore and Wilson 2000.)
13. Are milkweeds present in the roadside a threat to livestock on adjacent land?
Milkweeds present in roadsides are unlikely to be a threat to livestock on adjacent
property. Milkweeds are toxic to herbivores and are highly unpalatable to livestock.
If milkweeds are present in pastures or rangelands, most livestock avoid them.
Milkweed poisoning typically occurs only when livestock have no alternate food
source.
(Sources: Borders and Lee-Mader 2014; Fulton 1972; Pfister et al. 2002)
14. What are some adjacent land uses that benefit pollinators?
Pollinators benefit when adjacent land provides food, shelter, and water. Farms that
grow soybean, alfalfa, clover, cranberry, strawberry, and tomatoes, amongst other
crops, benefit from pollinators.
Shelter requirements for pollinators include dead plants and snags, leaf litter, and bare
soil. It is important to incorporate different canopy layers in order to attract a variety
of pollinators. Having multiple canopy layers acts as a natural wind breaker.
(Source: Ley 2008)
15. What is the minimum habitat size that would benefit pollinator along a highway right-
of-way?
Any habitat can be beneficial to pollinators, but as a general rule of thumb sites
should be 0.5 acre minimum. Sites of 2 acres or greater will provide the greatest
benefit and act as habitat corridors to other existing habitats.
The larger the planting area, the greater the potential benefit to pollinator species.
Habitat plots should generally be square, as opposed to narrow and linear to minimize
the edge effect. This is especially important in areas where pesticide use occurs, as
narrow, linear plots are more susceptible to pesticide drift.
(Source: USDA-NRCS, 2009)
16. Will local genotypes be used for planting pollinator habitat?
Using local genotypes helps ensure plants are well adapted to your region. ODOT is
determined to use native seed having Ohio genotypes when it is feasible. For
example, habitat plots in Ross County were successfully planted with locally sourced
seed. By protecting existing high-quality plant sources, these sites can act as a seed
source for future restoration projects.
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Frequently Asked Questions about Roadsides as Habitat for Pollinators
17. Why is it important to use native seed and local ecotypes when establishing pollinator
habitat?
Ecotypes or native seed is much more adapted to local conditions, such as drought,
than non-native plants. They develop deep, strong root systems that stabilize soils,
increase water infiltration, and do not require fertilizer and watering to get
established, as non-native plants often do.
Native plants can also tolerate poor soils and harsh growing conditions, such as those
along highway rights-of-way. Further, pollinators also tend to prefer native species to
those that have been introduced and, like the monarch butterfly; have often adapted to
specifically use these plants.
Local ecotypes are often even more adapted to the local conditions, and are more
likely to successfully establish. More importantly, using local ecotypes protects the
genetics of existing nearby populations.
(Sources: Bugg et al. 1997; Harper-Lore and Wilson 2000; Harrison 2014; O’Dell et
al. 2007; Quales 2003)
18. What should I do if I can't find an appropriate source for native, local ecotypes of seed
for my pollinator habitat?
Supplies of native plant materials are often limited, so plan your planting in advance
and coordinate with local vendors so that they can plan to have the plant materials
you need available. Many suppliers will take orders in advance, or will contract grow
the materials you request. In some areas, native plant materials are scarce, and
sufficient quantities may not be available. In these cases, some alternative options are
recommended:
Delay your project until the seed or plant materials become available.
Temporary vegetative cover can be established to protect the soils from
erosion, using annual species such as Avena sativa (common oats) or Lolium
multiflorum (ryegrass), as well as a number of annual forbs such as
Chamaecrista fasciculata (partridge pea), Coreopsis tinctoria (plains
coreopsis), and Gaillardia pulchella (Indian blanket).
Use native plants that do not necessarily originate from local genetic sources,
or that may not naturally occur in your area, but that are native to surrounding
areas. You can also use commercially available cultivars, but this is less
preferable due to concerns with potential dilution of local gene pools and
lowered adaptability.
If no other alternatives are available, non-native species that have been
proven to be non-invasive and/or sterile can also be used. Do not include
species that will aggressively compete with and displace native plant
communities, such as Agropyron cristatum (crested wheatgrass), Bromus
inermis (smooth brome), Dactylis glomerata (orchard grass), Leucanthemum
vulgare (oxeye daisy) Melilotus officinalis and M. albus (yellow and white
sweetclover), and Trifolium pretense (red clover).
The commercial availability of native plant sources is driven by the demand for those
resources. Producing native plant materials is a long-term process and can sometimes
be a risky investment for plant producers if they aren't sure about the long-term
demand for those plants/seeds.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 4-8
Frequently Asked Questions about Roadsides as Habitat for Pollinators
It is important that we continue to drive increasing demand for these native, locally
sourced plant materials to increase their availability over time.
(Sources: Hopwood et al. 2015; Steinfeld et al. 2007).
19. Is there a safe time to mow pollinator habitats that will be less harmful to pollinators?
While mowing at any time of year can result in mortality of pollinators, mowing at
the wrong time can result in high levels of insect mortality. For example, mowing
during the growing season, while plants are in bloom, can affect adult pollinators by
temporarily removing their nectar resources.
Mowing can also directly kill pollinators that are not able to quickly leave an area,
such as those in the egg or larval stages. Many native bee species nest in grasses and
woody vegetation throughout the winter.
It is ideal to mow once a year in very early spring, when pollinators are less active,
and vegetation is dormant. Mowing in small sections and rotating mown areas each
year may have the least impact on pollinators, as this leaves areas of refuge and food
resources.
(Sources: Hopwood et al. 2015; Hopwood 2013.)
20. Why use native plants, if they are more expensive than nonnative species?
There are many advantages to using native plants to establish pollinator gardens.
Native grasses and flowers are best adapted to local growing conditions, require
minimal inputs of water and nutrients for establishment, and are better able to tolerate
extreme weather events such as drought.
The root systems of native plants can increase water infiltration, which reduces runoff
and water pollution and keeps our waters cleaner.
A diverse native plant community can reduce soil erosion and resist weed invasions,
which can reduce maintenance costs.
Although native plants may cost more initially, they can provide cost savings over
time. Native plants can be aesthetically pleasing during the growing season while also
acting as snow fences in the winter, trapping and preventing snow from blowing
across roads.
Native plant communities also support more birds, pollinators, and other wildlife.
The use of native plants in roadsides can provide ecological benefits to the
surrounding landscape.
(Sources: Blumenthal et al. 2005; Bugg et al. 1997; Cramer 1991; Harper-Lore et al.
2014; Harper-Lore and Wilson 2000; Harrison 2014; Hopwood 2008; Johnson 2000;
Quales 2003; Ries et al. 2001; Tallamy and Shropshire 2009; Tilman et al. 2006;
Williams et al. 2011)
21. Are there plants that can be harmful to monarchs?
There are two known plant species that may negatively impact monarch populations.
Cynanchum louisea (black swallow-wort) and C. rossicum (pale swallow-wort) are
native to northern and southwestern Europe and were introduced into North America
during the 1800s. Both species have escaped from cultivated gardens or experimental
plantations and have begun to invade our native plant communities. Swallow-worts
look very similar to the monarch butterflies’ native host plant, Asclepias syriaca
(common milkweed), which can confuse egg-laying female monarchs.
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 4-9
Frequently Asked Questions about Roadsides as Habitat for Pollinators
If a female monarch lays eggs on the swallow-wort plants rather than milkweed, the
caterpillars will likely not survive because the swallow-wort is not a viable food
source for them.
(Source: Stone 2009.)
22. What are some native plant species that I can plant in my garden to help pollinators?
Ohio Pollinator Habitat Initiative Seed Mix Recommendations:
Early Season Flowering Plants:
Amorpha canescens (leadplant) Phlox pilosa (prairie phlox)
Baptisia tinctoria (wild Indigo) Tradescantia ohiensis (Ohio spiderwort)
Gaillardia spp. (blanket flower) Trifolium incarnatum (crimson clover)
Penstemon digitalis (foxglove beardtongue) Zizia aurea (golden Alexander)
Mid Season Flowering Plants:
Asclepias incarnata (swamp milkweed) Eryngium yuccifolium (rattlesnake master)
Asclepias syriaca (common milkweed) Heliopsis helianthoides (false (oxeye) sunflower)
Asclepias tuberosa (butterfly weed) Liatris spicata (dense blazing star)
Cassia fasciculata (partridge pea) Monarda fistulosa (Bergamot)
Coreopsis lanceolata (lanceleaf coreopsis) Ratibida pinnata (grayhead coneflower)
Desmanthus illinoensis (Illinois bundleflower) Rudbeckia serotina (black-eyed Susan)
Echinacea purpurea (purple coneflower) Silphium perfoliatum (cup plant)
Late Season Flowering Plants:
Agastache scrophulariaefolia (purple giant hyssop) Pycnanthemum virginianum (Virginia mountain mint)
Aster laevis (smooth aster) Solidago riddellii (Riddell’s goldenrod)
Aster novae-angliae (New England aster) Solidago rigida (stiff goldenrod)
Eupatorium maculatum (spotted Joe-Pye weed) Solidago speciosa (showy goldenrod)
Helenium atumnale (common sneezeweed) Verbena hastata (blue vervain)
Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 4-10
Frequently Asked Questions about Roadsides as Habitat for Pollinators
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Statewide Roadside Pollinator Habitat Restoration Guidelines and BMP’s Page 5-1
Evaluation Forms
Ohio Department of Transportation
Statewide Roadside Pollinator Habitat Program
June 2016
Evaluation Forms
Table of Contents
Potential Site Evaluation Form
Vegetation Evaluation Form
Insect Evaluation Form
Statewide Roadside Pollinator Program Potential Site Evaluation Form
Instructions: This evaluation form is intended to provide a method to ground-truth sites identified using GIS data and a measure of the suitability of each available site. Evaluate each site individually using the criteria listed under each category. Mark only one score for each of the criteria according to the most dominant feature of the entire site. Tally each of the scores for each category to determine the site ranking. (Good: 12-19; Better: 20-28; Best: 29-36) Site Name:___________________________________ County/Route/Section:______________________________________ District:_____________ Nearest Intersection:____________________ Mile Point:__________________________________ Reviewer Name:_________________________ Date:______________________________ GPS Collected: Y N
Existing Vegetation Conditions
Vegetation Health (1) - Vegetation appears stressed (2) - Some plants stressed, some healthy (3) - Majority of plants healthy and thriving
Vegetation Cover (1) - Thin and sparse (2) - Dense in some areas, patchy in others (3) - Thick and dense throughout
Type of Vegetation Cover (1) - Forested (2) - Herbaceous/shrub mix (3) - Herbaceous
Noxious/Undesirable Species (Percent Cover) (1) - Over 66% noxious (2) - 33-66% noxious (3) - 0-33% noxious
Soils Soil Compaction
(1) - New construction, bare ground (2) - Recent construction, compacted soils,
but has vegetation (3) - Relatively undisturbed, not compacted
Organic Matter (1) - Absent (2) - Moderate (3) - Abundant
Soil Content (Clay, Sand Ratio) (1) - 3:1 ratio (2) - 2:1 ratio (3) - 1:1 ratio
Notes:
Site Parameters
Primary Adjacent Land Use (1) - Dense non-native vegetation (2) - Agricultural use (3) - Natural area or preserve; non-mowed
field without dense weeds
Maintenance Equipment Accessibility (1) - Existing equipment can't access (2) - Limited accessibility (3) - Easily Accessible
Distance from the Roadway (1) - 0-10 meters (2) - 10-20 meters (3) - 20+ meters
Daily Sunlight Exposure (1) - 0-3 hours of sun (2) - 3-5 hours of sun (3) - 6+ hours of sun
Size (1) - Less than 1/2 acre (2) - 1/2-2 acres (3) - Greater than 2 acres
Total Score:
Statewide Roadside Pollinator Program
Vegetation Evaluation Form
Date:
INSTRUCTIONS: Fill out the following data sheets completely. When possible, use a GPS unit to gather coordinates. Site information will be used to assign location names. The participants involved will need to be listed in the data collection. Describe the initial observations in exact detail.
Site Information
County/Route: Site Contact: Mile Point: Contact Address:
District: GPS Coordinates:
Participants
1. 4. 2. 5. 3. 6.
Species Name Total Percent Cover
Included in Seed Mix? Notes
Species Name Total Percent Cover
Included in Seed Mix? Notes
Observational Notes
Statewide Roadside Pollinator Program Insect Evaluation Form
INSTRUCTIONS: Fill out the following data sheets completely. When possible, use a GPS unit to gather coordinates. Site information will be used to assign location names. The participants involved will need to be listed in the data collection. Describe the initial observations in exact detail.
Site Information County/Route: Site Contact: Mile Point: Contact Address: District: GPS Coordinates: Participants
1. 7. 2. 8. 3. 9. 4. 10. 5. 11. 6. 12. Initial Observations
Site History (i.e., age, former use of land, and any additional information):
Describe the current site, including nesting sites (bare ground, cane or hollow stems, wood piles, etc.), water resources, setting (urban/rural/agriculture, residential/garden/field, managed/unmanaged surroundings):
List floral resources (former, current, or potential) in garden/around site:
Date: Insect Evaluation Form
INSTRUCTIONS: Record the date and requested times. Circle the relevant weather information, and complete the habitat changes and weather anomalies (i.e., heavy precipitation, high winds, temperature extremes, etc.) since the last time you observed pollinators at the site. In the “Floral Resource” column, record the species of plant being observed. Count the total number of plants and the number of pollinators visiting each floral resource for ten minutes per plant species. Record the number of plants per observation (“# Plants/Obs.”). If you can’t determine which group a bee belongs to, record the bee in the “Other” column and note any distinctive characteristics, along with any additional comments. Please record additional blooming species at the bottom of the other side of this datasheet under “Additional Blooming Plants.”
County/Route: Observation Start Time: Observation End Time:
Weather Temp (°F): 50s 60s 70s 80s 90s 100+ Wind: Still Light Breeze Windy Gusty Sky: Clear Partly Cloudy Mostly Cloudy Overcast Habitat Changes (Since last observation or collection date):
Floral Resource (Genus Species)
# Plants/ Obs. # Butterflies # Native Bees # Honey Bees Other- Describe in Notes
Observational Notes
Additional Blooming Plants