RIGHT TREE,RIGHT SPACE

PRACTICAL CONSIDERATIONS IN TREE SELECTION AND PLANTING

Janine Lester, Landscape Design Consulting Board Certified Master Arborist, Municipal Specialist

MA-4838BM

Introduction

This presentation is about:1. Defining objectives,2. How to choose a tree,3. How work within limitations of the planting location.

Right Tree - Right Space:What does it mean?

1. “Right tree - Right Space” is based on meeting a specific set of objectives.

2. Our primary responsibility in matching the tree to the space is in first defining, then in meeting, these objectives.

Proper tree spacing based on mature canopy spread

Right Tree - Right Space

1. Defining Goals 2. The Right Tree

Tree Attributes• Above ground• Below ground

3. The Right Space Site Attributes Design Theory

Defining Objectives

Homeowners may have different objectives than the city does

First, define the objective.

Trees work for you.What is this tree’s

JOB?

Homeowners may have resourcesthat the city doesn’t have

Reasons homeowners plant trees

Reasons cities plant trees

Environmental Benefits:• Environmental Cooling / Temperature Reduction• Extended Wear Duration of Paved Surfaces

• Wind Control• Air quality / Pollution Reduction• Water Quality / Erosion Control

Economic / Social / Psychological Benefits:• Economic Stability and Investment• Increased Property Values

• Improved Aesthetics / Visual Screening• Improved Health / Recreational Opportunities

• Crime Reduction• Wildlife Habitat

Wait, slow down…

Trees provide many benefits. They give shade, reduce temperatures, and increase asphalt durability. They lower wind speed, produce oxygen, and filter out pollution. They improve water quality by filtering storm water.Studies also show a direct correlation between urban trees and economic growth and stability. Shoppers spend more time and money in shopping districts with trees. Trees mitigate eyesores and increase property value as much as 12%, and trees reduce all types of crime.

Benefits of Urban Trees

What tree should I plant?

What is the

objective?

Sustainability/Diversity

Diversity: Difference or variety.

Sustainability: The capacity to endure.

-The American Heritage Dictionary

What is good landscape design?

“The best landscape design is one that meets all the defined objectives, within

the limitations of the site, not just at the time of installation, but for the

foreseeable future.”

How to Achieve DiversityFrank Santamour, 1990

United States Arboretum

10-20-30 Rule:• No more than 10% any one SPECIES• No more than 20% any one GENUS• No more than 30% any one FAMILY

Monoculture:Growing a single plant species

over a wide area for a long time

–Monocultures increase tree susceptibility to disease and insect damage.

–With increased susceptibility comes increased need for subsidies and interventions.

Ok, but I still don’t knowwhat kind of tree to plant.

Nonexistant Natives

• A native tree that none of your IMMEDIATE NEXT DOOR neighbors already have growing on their property.

• A native tree that is UNDER REPRESENTED in your neighborhood.

• A native tree that isn’t growing ANYWHERE in your neighborhood.

Why Natives?

• Native plants are acclimated to local conditions.

• Native species are threatened by development and the introduction of invasive or aggressive non-native species into our environment.

• Native wildlife may require native species for food, shelter and nesting sites.

ArchaeopterisArchaeopteris was the first modern tree. It had an extensive root system, produced leaves, grew to a height of 30 meters or more, and had laterally growing branches. A swelling at the base of the branches formed a supporting collar, while layers of wood dovetailed into the trunk to give additional strength.

Native Trees in Virginia

• Chionanthus virginicus

• Fagus grandifolia

• Liquidambar styraciflua

• Liriodendron tulipifera

• Magnolia grandiflora

• Nyssa sylvatica

• Oxydendrum arboreum

• Quercus phellos

• Taxodium distichum

• Tilia americana

More Native Trees in Virginia

• Amelanchier arborea

• Asimina triloba

• Castanea pumila

• Carpinus caroliniana

• Diospyros virginiana

• Cercis canadensis

• Ilex opaca

• Juglans nigra

• Ostrya virginiana

• Tsuga canadensis

Is it ever okay to plant non-native trees?

Native Habitats:They don’t make them

like they used to

Native Climate?You’re Getting Warmer!

1948 2006

Know Thy Tree

Oka

OKAY, WHATEVER,DUDE…I HAVE NEEDS TOO!

Part 2: The Right Tree

• Defining Goals

– Sustainability

– Diversity

• Tree Attributes

– Above ground

– Below ground

Selecting Quality Trees

Which is better?

Live Crown Ratio?

Mature Tree Attributes

Above Ground Attributes

a) Height

b) Width (Habit, Spread)

c) Assets

d) Liabilities

Small: Under 25’Medium: 25-40’Tall: Over 40’

Mature Tree Attributes

Above Ground Attributes

a) Height

b) Width

c) Assets

d) Liabilities

Mature Tree Attributes

Above Ground Attributes

a) Height

b) Habit, Spread

c) Assets

d) Liabilities

Desirable Attributes

ShadeFlowers/FragranceEdible FruitFast GrowthFall ColorInteresting BarkScreeningHabitat

Mature Tree Attributes

Above Ground Attributes

a) Height

b) Habit, Spread

c) Assets

d) Liabilities

Undesirable Attributes

ShadeFlowers/FragranceEdible FruitFast GrowthFall ColorInteresting BarkScreeningHabitat

More Searchable Attributes

• Fast/Slow Growth Rate• Allergen Producer• Poisonous• Strong/Weak Branch Attachments• Toxic Emissions• Deer Resistance• Fire Resistance• Susceptibility to Disease/Insects• Compartmentalization of Decay• Thorny/Spiny

Part I: The Right Tree

• Defining Goals

– Sustainability

– Diversity

• Tree Attributes

– Above ground

– Below ground

Below Ground Attributes

1. Root Growth / Habit

2. Soil Tolerances

• Wet / Low O2

• Dry / Dense

• Salt / pH

Girdling Roots:

The #1 Root Problem

What causes circling roots?

Once circling, Always circling.

From this…

…to this

So, what’s the solution? No more container grown trees?

Harvesting a field-grown nursery tree with a hydraulic tree spade

OUCH!

ii

I can’t feel my

legs!

B&B trees have problems too.

Root Growth Habit

Actual root structure looks more like this…

Or this…

Or this.

“Poor Soil Conditions are the #1 Cause of Tree Blow-Downs in Wind Storms”

Is there any way to know what you’re getting?

ROOT WASHING: A CASE STUDY

A B&B tree being root washed. It will be soaked and hosed down to remove the soil and

reveal the root mass.

Even a huge rootball is easy to lift when you

get rid of the soil.

Seven months later, the tree is thriving. No staking needed!

Good Root Structure

Good Root Structure

NO root structure!

Bottom line?Give ‘em room.

Below Ground Attributes

1. Root Growth / Habit

2. Soil Tolerances

• Wet / Low O2

• Dry / Dense

• Salt / pH

Trees Tolerant of Salt• Horsechestnut (Aesculus hippocastanum)• Serviceberry (Amelanchier canadensis.)• Cherry Birch (Betula lenta)• Cockspur Hawthorn (Crataegus crusgalli var.inermis)• Maidenhair Tree (Ginkgo biloba)• Honeylocust (Gleditsia triacanthos var.inermis)• Kentucky Coffeetree (Gymnocladus dioica) • Witchhazel (Hamamelis spp.) • Eastern Redcedar (Juniperus virginiana) • Magnolia (Magnolia spp.) • Black Gum (Nyssa sylvatica) • White Oak (Quercus alba) • Red Oak (Quercus rubra) • Japanese Pagodatree (Sophora japonica)

Trees for Wet Soils

• Maple (Acer) • Serviceberry (Amelanchier)• Birch (Betula)• Fringe Tree (Chionanthus)• Ash (Fraxinus)• Crape Myrtle (Lagerstroemia)• Sweet Bay Magnolia (Magnolia virginiana)• Black Gum (Nyssa sylvatica)• Willow (Salix)• Bald Cypress (Taxodium)

*Drought Tolerant Trees• Black walnut Juglans nigra • Goldenraintree Koelreuteria

paniculata • Flowering crabapple Malus spp. • Chinese pistache Pistacia chinensis • London planetree Platanus x

acerifolia • Amer. sycamore Platanus

occidentalis • Black locust Robinia pseudoacacia • Red oak Quercus rubra • Japanese pagoda tree Sophora

japonica • Lacebark elm Ulmus parvifolia • Japanese zelkova Zelkova serrata

• Acer ginnala • Ohio buckeye Aesculus glabra • Pawpaw Asimina triloba • Chinese chestnut Castanea

mollissima • Northern catalpa Catalpa speciosa • Common hackberry Celtis

occidentalis • Red bud Cercis canadensis • Yellowwood Cladrastis kentukea • Smoke tree Cotinus coggygria • Hawthorn Crataegus spp. • European beech Fagus sylvatica• Ginkgo Ginkgo biloba • Thornless honeylocust Gleditsia

triacanthos var.inermis

*No water needed

Refer to online tree selectors!

• Virginia Tech• NCSU• Morton Arboretum• Urban Forestry South• Virginia Cooperative Extension

Part II: Site Attributes

The Three Primary Site Considerations

SUN EXPOSURE

It’s not just about

hours per day

Influences on Sun Intensity

• LATITUDE: The sun is

most intense along the

equator

• ALTITUDE: UV intensity

increases with altitude

• SEASON: UV light is more

intense over a longer

duration in the summer

• WEATHER: Clouds reduce

the intensity of UV rays

• REFLECTION: Snow,

sand, water, and cement

are all highly reflective

• TIME OF DAY: The sun is

most direct at noon

More things that influence the intensity of sunlight

–Changes in the earth’s orbit

–Changes in the atmosphere

–Changes in the sun itself

Full Sun – Full Shade

• Full Sun: At least 6 hours of direct sun.

• Partial Sun: 3 - 6 hours of sun each day.

• Partial Shade: Under 3 hrs of direct sun.

• Dappled Sun: Only filtered sun.

• Full Shade: No intense afternoon sun.

Soil: what’s the dirt?

1. MOISTURE: Not just rainfall, but

access to supplemental water

2. STRUCTURE: What’s it made of, and

what is its bulk density

3. pH and NUTRIENTS: Before you buy

fertilizer, determine need

4. VOLUME: The more, the merrier

Soil Moisture

• It’s not just about rainfall. Newly planted trees should have access to supplemental irrigation during the critical establishment period.

• Smaller trees will establish faster than larger trees will, and can easily eclipse them in size in a few years.

Water Needs of TreesPlanted Within the Past 2 Years

*5 gallons per inch, twice weekly:• No mulch on top of root ball! • Apply water SLOWLY to the top of the root

ball and surrounding soil. • More FREQUENT irrigation is even better

for trees planted in the last several months. * UF Dept of Ornamental Horticulture

Soil Texture Test

Soil Horizons

Compacted soils

What is soil compaction?

Soil compaction, measured in bulk density, is the destruction of soil aggregates and collapse of large aeration pores that results from

the translocation and resorting of soil particles (Coder 2000).

GLBD

Under compaction, soil reaches a threshold known as

GROWTH- LIMITING- BULK- DENSITY (GLBD), beyond

which roots can no longer elongate.

Why is it a problem?

Compaction disrupts respiration processes that power every function of the tree.

Compacted soil is associated with reduced vigor and tree decline.

Root death resulting from crushing or cutting can lead to tree failure.

Can soil be decompacted?

Artificial Decompaction:

Mulch had a significant impact. Soil moisture was significantly

higher under mulched treatments,and leaf water

potentials were improved by mulch treatments (Wells,

2006).

Tilling and organic matter incorporation is one of the only techniques that effectively reduces bulk density, alleviates soil compaction, and improves soil fertility (Patterson, 1975).

Soil amendments are one of the few methods known to reduce soil bulk density and improve plant performance (Day and Bassuk, 1994).

Soil pH and Nutrients

Construction removes the organic layer, taking away the nitrogen, sulfur, phosphorous, and other nutrients that

would otherwise return to the soil (Craul 1985). Decomposing organic matter improves soil structure and

water-holding capacity. These benefits are not realized in urban soils.

Is pH different in urban soils?

Urban soils are more alkaline than natural soils. Urban soils in major US cities were observed to have average pH values of 7.6 - 8.0 . Native forest soils have a pH of only 4.0 (Bockheim 1974; Craul and Klein 1980).

SOIL VOLUME:THE MORE, THE MERRIER

“The major impediment to the establishment of trees in paved

urban areas is the lack of adequate soil volume for root growth.” –Urban Horticulture

Institute, Dec. 2000

Newer guidelines recognize the need for root space in city sidewalk construction

Increased soil volume reduces risk of blow over:

• Over 75 cubic feet:

91% survival

• 40-75 cubic feet:

73 survival

• Under 40 cubic feet:

64% survival

The Effects of Restricted Roots

Other Site Attributes

• Overhead or Underground utilities

• Septic Fields• Proximity to Buildings• Herbicides Nearby• Easements and RoWs• Slope Aspect• Windy• Other Plants• Salts

• Heat Venting• Domestic Pets / Livestock• Fertilizers/Chemicals• Air Pollution• Light Pollution• Vista• Targets (Risk Potential)• Historic Value• HOAs/Regulations• Soil-Borne Pathogens

Elements and Principles of Design

• Line• Form• Texture• Color• Weight

• Proportion• Order• Balance• Repetition• Unity

What is good landscape design?

“The best landscape design is one that meets all the defined objectives, within

the limitations of the site, not just at the time of installation, but for the

foreseeable future.”

Landscape Design

One of the first principles of good landscape design is SUSTAINABILITY.

Designing “for the foreseeable future” takes into account the mature size of a

tree, and the likelihood that the site conditions will change over time.

Don’t let this happen to you!

QUIZ!

RICHMONDTREE STEWARDS

WHY WEDO WHAT WEDO

Thank You!talktojanine@hotmail.com