Best Management Practices for Florida turfgrasses – Fertility and Cultural

Best Management Practices for Florida turfgrasses – Fertility and Cultural

http://turf.ufl.edu

LAWN

Have you scalped the lawn? Used weed and feed more

than 2 times a year? Water more than 2 times a

week? Fertilize with quick release

fertilizer?

Then lets SHAPE UP!

Benefits of Turfgrass Functional Benefits

Stormwater Runoff Reduction

Soil Erosion Dust Stabilization Heat Dissipation

Aesthetic Benefits Safe Play Area Community Pride Increased Property

Values Compliments and

ties together the rest of the landscape

Components of best management practices

Right plant, right place Fertility practices Irrigation practices Mowing practices Pesticide spraying

Which Grass Do You Want to Use?

• Bahiagrass

• Bermudagrass

• Centipedegrass

•St. Augustinegrass

• Zoysiagrass

St. Augustinegrass(Stenotaphrum secundatum)

Advantages Good shade

tolerance Good salt

tolerance Tolerant to wide

range of soil pH Establishes

quickly from sod Dark green color

Disadvantages–Poor cold tolerance

–Poor drought tolerance

–Poor wear tolerance

–Forms excessive thatch

–Susceptible to chinch bugs

St. Augustinegrass(Stenotaphrum secundatum)

St. Augustinegrass Cultivars

Floratam no longer chinch bug resistantpoor cold and shade

toleranceRaleigh cold hardy

poor chinch bug resistanceBitterblue good shade tolerance, blue green colorClassic good cold tolerance Amerishade dwarf with good shade tolerance

•Captiva New dwarf cultivar with great shade tolerance and chinch bug resistance•Seville Great shade tolerance prone to thatch and webworms•Delmar cold tolerant- good for sun too

St. Augustine dwarf cultivars

Zoysiagrasses (Zoysia spp.)

Advantages Tight low growing turf Good shade tolerance Resists weeds Good traffic tolerance Disney grass

Zoysiagrasses (Zoysia spp.)

Disadvantages Slow growing Thatch issues Water needs Fertilizer needs Billbugs Nematodes

Zoysiagrasses cultivars

Empire El Toro Ultimate flora

Lush look of a Northern-type lawn grass for warm-season climates.

Easily replaces St. Augustine grass as a residential turfgrass option.

Establishes quicker than most other zoysia grasses.

Bahiagrass(Paspalum notatum)

Advantages Good drought tolerance Low fertility

requirements Low maintenance Tolerant of sandy,

infertile soils Establishes from seed

Bahiagrass(Paspalum notatum)

Disadvantages Produces abundance of

seedheads Open growth habit

encourages weed competition

Susceptible to mole crickets Coarse stems are difficult to

mow Not wear tolerant

Centipede grass Advantages

Slow growing Good drought tolerance Low fertility requirements Low maintenance Tolerant of sandy, infertile soils

Hammock is a good cultivar

Centipede grass Disadvantages

Poor shade tolerance Nematodes Can be over managed

Fertilization

Goals of fertility programs1. To produce healthy, stress-

tolerant turfgrass2. To protect the

environment

Turfgrass Fertility Considerations

Soil testing How to apply fertilizer to not pollute Fertilizer source (quick-release vs.

slow-release) Application amount Application timing Fall fertility Fertilizer storage

Know Your Soil Soil testing should

provide the basis for determining a fertility program

This includes pH testing as well as extractable levels of macro and micronutrients

Do not soil test for N, as it is very mobile

pH If you soil pH is too low less than 6 you will

need to apply Lime Only apply lime with recommendations

from your soil test Use either calcitic limestone or dolomite to

lime Water in with ¼ inch of irrigation It will take 4-6 weeks for you to get the pH

were it needs to be

The Fertilizer Bag

Numbers refer to percent nitrogen, phosphorus, potassium in the bag

Example: 15-0-15 has 15% N, (or 7.5 lbs. in a 50 lb. bag) 0% P, 15% K as K2O5

Nutrient sources also listed

Turfgrass Fertility Considerations

How to apply Fertilizer source (quick-

release vs. slow-release) Application amount Application timing Fall fertility

How To Properly Apply Fertilizer Be careful not to apply fertilizer particles

onto sidewalks, roadways, or other impervious surfaces where they might wind up in the storm drain

How To Properly Apply Fertilizer Use a deflector shield when fertilizing near

water bodies- this will allow for a 3’ ring – without a shield, leave a 10’ ring

How To Properly Apply Fertilizer Irrigate fertilizer in with only enough

water to move granules off of leaves (~1/4” water)

Elements Required for Turfgrass Growth

Macronutrients:

Nitrogen

Phosphorus

Potassium

Calcium

Magnesium

Sulfur

From Environment:

Carbon

Hydrogen

Oxygen

Micronutrients:

Iron

Manganese

Boron

Copper

Molybdenum

Zinc

Nickel

Application Amount Depends on percentage slow-release N No more than ½ lb. N 1000 ft2 if quick-

release Up to 1 lb. N 1000 ft2 if slow-release Better to apply smaller amounts more

frequently for optimal physiological functioning of turf

T-Timing 1. The first fertilization is in the

Spring -early April2. Then May with slow release3. Fall fertilization is done in

September-October4. Weed control is addressed in

late February early March

Current UF/IFAS Fertility Recommendations(lbs. N 1000 ft-2 yr-1)

St. Augustinegrass:North FL: 2-4Central FL: 2-5South FL: 4-6

Current UF/IFAS Fertility Recommendations(lbs. N 1000 ft-2 yr-1)

Bahiagrass:North FL: 2-3Central FL: 2-4South FL: 2-4

Current UF/IFAS Fertility Recommendations(lbs. N 1000 ft-2 yr-1)

Centipedegrass:North FL: 1-2Central FL: 2-3South FL: 2-3

Current UF/IFAS Fertility Recommendations(lbs. N 1000 ft-2 yr-1)

Zoysia grass:North FL: 2-4

Central FL: 3-6

South FL: 4-6

Current UF/IFAS Fertility Recommendations(lbs. N 1000 ft-2 yr-1)

To apply 1 pound of NITROGEN per 1000 square feet

Take the percentage nitrogen from the fertilizer label 10-2-10 and divide that into 100. The result will equal the pounds of FERTILIZER to apply to 1000 square feet.

For a 15-0-15 15/100 = 6.5 pounds of fertilizer to 1000 square

How Much Phosphorus Do We Need in Florida?

• P fertilization should be based on soil test results

• If a soil test indicates P is adequate in soil, use a fertilizer with no more than 2% P

• P may be required in greater amounts during establishment of lawns

Fertilizer Rulein Florida on Phosphorus

This rule limits fertilizers that can be sold for use on lawns to those that contain low or no phosphorus (2nd number on the bag), and limits the total annual amount of phosphorous that can be applied to a home lawn.

You are allowed to apply 1 pound of nitrogen per 1,000 square feet of lawn each time you apply fertilizer if the nitrogen is in a slow-release form, or 0.7 pounds of nitrogen if you are using a quick-release source.

Potassium Provides Increased Tolerance to Many Stresses

• Helps turf maintain water balance• Functions in cellular activities such

as photosynthesis• Can enhance cold tolerance and

spring green-up

Other Considerations for Fertility: Irrigation

Even if fertilizer is applied at proper rates, too much water following fertilizing can result in leaching or runoff

Irrigate fertilizer in with ¼” of water

Don’t fertilize during a heavy rainfall

It’s raining out- should we leave the sprinklers on?

An efficient watering program must include:

How frequently to water

how much to water time of day to water

How Often to Water The most efficient

way is to apply water when turf begins to show signs of stress: bluish gray

color footprints

remain leaf blades

folded in half

How Much to Water•An efficient watering only wets the turfgrass root zone, does not saturate the soil, and does not allow water to run off.

•Apply 1/2” to 3/4” when turf shows symptoms of wilt and do not apply any more until water stress symptoms are again noticeable.

Short, frequent irrigations

Longer, less frequent irrigations

Time of Day To Water

Wet grass = disease opportunity

Dew point should not be extended – grass must dry out

Best time to water is just before or at sunrise

Irrigation System Efficiency One of the most

important things to do during a drought is to check the efficiency of your irrigation system

We are under Watering Restrictions Water only one time per week. Even addresses Sunday Odd addresses Saturday No watering between 10 am and 4 pm Check with GRU or St. John’s River

Water Management district for more information.

Mowing

• Don’t mow grass when wet

•Keep mower blades sharp!

Mowing Mow at highest recommended height

for species Don’t remove more than 1/3 of the

leaf blade at any one time Leave clippings on the ground Increase mowing height under any

environmental stress (shade, drought, etc.)

Influence of mowing height on rooting depth

Mowing Under Drought Conditions

Grass growth is reduced during drought Therefore, mowing needs are reduced You should mow less often, but at the

highest recommended height for your grass. This will help to encourage a deeper root system and place less stress on the grass

Keep your mower blades at their sharpest to further reduce stress on the grass

How Do I Manage Turf in the Shade?

Remove shade sources (trimming trees) Reduce traffic in shaded areas Increase mowing height if possible –

more shoot tissue for photosynthesis will help turf perform better

Reduce irrigation in shaded areas Reduce fertilization – trying to promote

shoot growth with high fertility will further stress the grass

Shade Tolerant Turf

St. Augustinegrass = zoysiagrassCentipedegrass

BahiagrassBermudagrass

St. Augustinegrass Shade Tolerance

Captiva, Seville, Delmar, Bitterblue

Palmetto Floratam

Weeds Broadleaf Sedges Grass weeds

Weed Control Begins With Proper Management Proper Turfgrass Selection

This results in thin, weak turf that is very susceptible to weed invasion

Proper Cultural Practices Proper fertilization, watering, mowing, and control of

other pests are required to produce a dense turf that will prevent weed infestation

Sanitation Many times we introduce the weeds

Chemical Controls Selective, Non-selective Contact, Systemic Pre-emergence

applied prior to weed seed germination

Read your herbicide label very carefully

Hawksbeard Spreading Dayflower

Chamber bitterDollarweed

crabgrass

Crowfootgrass

Sandspur

PendamethalinHalts crabgrass preventer

Globe SedgeNutsedge

BasagranManage Image

Hand weeding can work!

Diseases

Gray leaf spot azoxystrobin, propiconazole, thiophanate methyl, trifloxystrobin.

Diseases Brown Patch now Large patch

Cool weather disease mancozeb, azoxystrobin propiconazole thiophanate methyl

Insects

Chinch bugs

Suck the plant juices from grass (generally on nodes of runners) resulting in yellowish to brownish patches

Damage often first noticed in water stressed areas along edges of lawns Treat with triazicide or bifenthrin

Chinch bugs

Tropical Sod Web Worms

Summer and fall Notched feeding on

blades Associated with

moths Dipel or Sevin

Grubs Grass thins, yellows,

wilts, dies. No roots Many different beetle

culprits Grub Ex

Inspecting for GrubsInspecting for Grubs

Treat with labeled pesticideTreat with labeled pesticide

Monitoring for Turf PestsMonitoring for Turf Pests

Weekly pest monitoring is recommended

Monitoring Chinch Bugs

1) Insert open ended metal can 2 inches into soil1) Insert open ended metal can 2 inches into soil in suspected areasin suspected areas

2) Fill can with water, chinch bugs will float2) Fill can with water, chinch bugs will float

3) Wait 5 minutes 3) Wait 5 minutes then countthen count

4) Repeat in 3 - 4 4) Repeat in 3 - 4 locationslocations

In general, healthy turf is In general, healthy turf is better able to withstand pest better able to withstand pest pressure than stressed turfpressure than stressed turf

Follow guidelines for growing healthy Follow guidelines for growing healthy turf printed in the Florida Lawn turf printed in the Florida Lawn

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