Table of Contents

You Can Have a Healthy Lawn and Healthy Water

Page 1

Why Fertilize Your Lawn?

Page 2

Step 1 — Getting Ready to Fertilize

Page 3

Test Your Soil

Know When to Apply Fertilizer

Step 2 — Determining How Much to Buy

Page 5

Step 3 — Selecting Fertilizer

Page 6

Read the Label

Choose Slow-Release Fertilizer

Tips for Newly Planted Turf

Additional Tips

Labeling Requirements Rule

Step 4 — Applying Fertilizer

Page 9

Calculate Application Rates

Apply Using a Spreader

Water-In Fertilizer

Step 5 — Maintaining a Healthy Lawn

Page 12

When Mowing

When Watering

Irrigation System Tips

Resources

Page 15

Glossary

Page 16

Tips to Remember

Page 17

You Can Have a Healthy Lawn

and Healthy Water

he Southwest Florida Water Management District (District)

manages the water resources for all or part of 16 counties in west-

central Florida. The goal of the District is to meet the water needs of

current and future water users while protecting and preserving the water

resources within its boundaries.

Recent studies have shown that nitrate levels are rising in many local

water bodies. Nitrate is a form of nitrogen that is found in inorganic

fertilizers. Nitrogen is needed to help lawns stay healthy. When fertilizer

is applied correctly, the grass will use all the nitrogen. If applied

incorrectly, nitrogen can leach into our groundwater or wash off the

land and into lakes, rivers and the gulf. Once in our water bodies,

nutrients from fertilizer may cause algae to grow. Algae can form large

blooms that shade out beneficial aquatic plants and use oxygen that fish

need to survive.

You can help protect water quality and have a beautiful lawn by following

the Florida-friendly fertilizing guidelines* outlined in this booklet.

Check with your local city or county to see if your area has a more

restrictive fertilizer ordinance. Visit WaterMatters.org/fertilizing for

detailed information on fertilizing for your grass species, your location

in the state and your desired level of lawn care.

Fertilizing appropriately is one of the nine Florida-Friendly LandscapingTM

principles — a set of guidelines that help protect natural resources

while having a beautiful landscape. For more information, visit

WaterMatters.org/yards/.

* Guidelines established by the University of Florida’s Institute of Food and Agricultural Sciences

(UF/IFAS) and the Florida Department of Environmental Protection (FDEP).

See glossary on page 16 for definitions of bolded words.

Why Fertilize Your Lawn?

ertilizers are designed to make your lawn green, healthy and more

stress-tolerant. To maintain health, turfgrass needs nutrients, some

of which are supplied by your soil. In some cases, fertilizer is necessary

because your soil cannot supply the grass with all the nutrients it needs

to stay healthy and green over the years. When needed, fertilizer should

be applied according to UF/IFAS and FDEP guidelines. If applied

correctly, fertilizer can help your lawn stay healthy by:

• Increasing leaf and root growth.

• Aiding in the recovery from pest damage and environmental

stresses.

• Reducing and controlling weeds.

• Replacing nutrients lost to plant growth and leaching.

If your landscape is healthy and its

appearance is pleasing, you may not

need to fertilize the entire site, only

problem areas. Take samples of problem

areas to your local Extension office to

check for pests and pH deficiencies.

STEP 1 GETTING READY TO FERTILIZE

Test Your Soil

A good approach to proper

fertilization is to start with a

soil test. Many Florida soils are

naturally high in phosphorus,

one of three major nutrients

in fertilizer. If your soil test

shows an adequate level of

phosphorus, choose a fertilizer

blend that does not contain

it. Your soil test will also tell you about your soil’s pH (acidity or

alkalinity) levels and other nutrient levels. You can get information

on obtaining a soil test from your county Extension office or visit

WaterMatters.org/yards.

Know When to Apply Fertilizer

To prevent fertilizer from washing into water bodies, it’s important

to know the right time to fertilize. Follow these tips before

fertilizing:

• Consider the time of year, climate, soil type and, most important,

type of grass and health or condition of the lawn before applying

fertilizer.

• Fertilize only when the grass is actively growing. For instance,

during the winter, grass is dormant in many areas of Florida;

therefore, fertilizer is not necessary. Fertilizer applied when grass

is not growing wastes your money and time, since it will not be

beneficially used by the grass. Instead, it will leach through the

soil or run off and pollute nearby water bodies.

• If your lawn has problem areas, find out if this is related to a pest,

soil or environmental problem such as excess shade or the uneven

distribution of irrigation water. These problems should be corrected

and not just masked by fertilization.

• If your household uses reclaimed water, check with your utility to

determine if your reclaimed water has nutrients such as nitrogen

and phosphorus, which are also in fertilizer. If so, you may not need

to fertilize as much.

• Do not fertilize if rain is predicted in the next 24-36 hours or when

a heavy rain, tropical storm, hurricane or flood is predicted.

STEP 2 DETERMINING HOW MUCH TO BUY

o avoid storing leftover fertilizer, decide how much you need before

you make a purchase. Don’t guess! Measure your property and

calculate the total square footage of turfgrass. Do not include landscape

plants in the area to be fertilized.

35 ft.

65 ft.

65 ft. x 35 ft. = 2,275 square ft.

Figure 1 - If the lawn is made up of

irregular-shaped areas, approximate a

65 ft.

square or rectangular shape and use

these measurements for the calculation.

35 ft.

50 ft.

75 ft.

75 ft. x 50 ft. = 3,750 square ft.

Figure 2 - If the lawn is a simple square

or rectangle, multiply the length and

width (in feet).

STEP 3 SELECTING FERTILIZER

Read the Label

All fertilizer labels have three bold numbers. The first number on the

label represents nitrogen, the second number represents phosphorus

and the third number represents potassium. These are the three major

nutrients your lawn needs to thrive.

In general, select a

fertilizer where the first

and third numbers on

the label are equal or in a

RATIO

2:1 ratio and the middle

number is zero or as low

as possible.

NITROGEN

(symbol N) for shoot growth

Look for a fertilizer

and green color.

where the ratio of

PHOSPHORUS (symbol P) for root growth

and cellular functioning.

nitrogen to phosphorus

(the first to second

POTASSIUM

(symbol K), sometimes called

potash, for root development,

number) is a minimum

improved stress tolerance

of 4 to 1. For example, a

and disease resistance.

12-3-10 and a 15-0-15

For example, a 100-pound bag marked “12-3-10”

fertilizer would follow

has 12 pounds of nitrogen (12%), 3 pounds of

this recommendation.

phosphorus (3%) and 10 pounds of potassium

(10%). The remaining 75 pounds are made up

of other nutrients, conditioners and fillers.

Their purpose is to help distribute the fertilizer

evenly and prevent chemical burn.

Nitrogen and phosphorus may cause

water pollution if misapplied.

Choose Slow-Release Fertilizer

Most home lawn fertilizers contain some slow-release nitrogen.

It takes longer for your yard to benefit from slow-release nitrogen,

but the effects will last longer. Many of these fertilizers provide

fertilization for 60 days or longer, depending on environmental

conditions. As a result, fewer nutrients may be wasted or lost as

pollutants.

To find a slow-release fertilizer, look for these terms on the

product or fertilizer tag for nitrogen:

• Timed-release, slow-release or controlled-release

• Water insoluble nitrogen

• Isobutylidene diurea (IBDU)

• Ureaform (UF)

• Nitroform

• Sulfur-, polymer-, plastic- or resin-coated urea

Tips for Newly Planted Turf

• Do not fertilize newly planted lawns (whether seeded or sodded)

until 30-60 days after planting. This ensures that there is an active

root system to absorb the nutrients. Apply a complete (nitrogen,

phosphorus and potassium) slow-release nitrogen fertilizer to

provide 1 pound of actual nitrogen per 1,000 square feet.

• After the initial fertilization, follow UF/IFAS guidelines for your

grass species for fertilizing established turf.

Additional Tips

• Do not use weed and feed products. They may harm landscape

plants if roots extend into the lawn area.

• Consider applying a soluble or chelated iron source to green the

lawn without increasing growth in the summer.

• Avoid liquid and soluble nitrogen fertilizer. These products should

be used only by professional turfgrass managers.

Labeling Requirements Rule

The Florida Department of Agriculture and Consumer Services

passed a rule regulating labeling requirements in the state for urban

turf fertilizers. The new labeling requirements will make it easier for

homeowners to find lawn fertilizers with both slow-release nitrogen

and low phosphorus. This rule is intended to reduce potential pollution

that might result from application of excess fertilizer to lawns.

• Rule for phosphorus — application rates are not to exceed 0.25 pound

per 1,000 square feet per application and are not to exceed 0.5 pound

of phosphorus per 1,000 square feet per year.

• Rule for nitrogen — application rates for slow-release nitrogen are not

to exceed 1 pound per 1,000 square feet per application. Application

rates for quick-release nitrogen are not to exceed 0.7 pound per 1,000

square feet per application.

Do not over-fertilize. Repeatedly

using large amounts of nitrogen

fertilizer can increase pests and

environmental stress problems.

STEP 4 APPLYING FERTILIZER

hen applying fertilizer, the most important thing to remember is

to read and follow the instructions on the fertilizer bag. Proper

application will ensure maximum coverage, resulting in a healthy lawn

while protecting water bodies.

Calculate Application Rates

To determine the correct amount of fertilizer per 1,000 square feet,

divide 100 by the percentage of nitrogen in the bag. For example, a

fertilizer with a 15-0-15 label contains 15% nitrogen, 0% phosphorus

and 15% potassium. Divide 100 by 15 to get 6.6; this is the number of

pounds of slow-release fertilizer needed to apply one pound of nitrogen

per 1,000 square feet. This works for any fertilizer product or amount

of nitrogen.

Nitrogen application rates vary according to type of turf and location in

the state. Please visit WaterMatters.org/fertilizing for more information

on calculating application rates.

Apply Using a Spreader

• Overlap your spread pattern by

applying half the fertilizer in

one direction and the rest in the

opposite direction. This will ensure

an even application and avoid the

appearance of a striped lawn. Break

up any clumps so that the fertilizer

will not get clogged in the spreader.

• Turn off the spreader before stopping and when making turns. Then,

turn it back on after you have resumed walking. Shut off the spreader

when passing over pavement.

• Use a deflection shield when using a spreader near sidewalks,

driveways and water bodies. This will avoid spreading fertilizer

granules onto impervious surfaces or into water bodies.

• Clean spreader on the lawn, not on the sidewalk or driveway.

Fertilizer granules should never be left on impervious surfaces.

Water-In Fertilizer

Water-in your fertilizer after application with no more than ¼ inch of

water. To determine how much this is, perform a catch-can test. Do this

by placing empty cat food or tuna cans around the perimeter of your

sprinkler or irrigation system and time how long it takes to fill them

to this depth (¼ inch). Do this before fertilizing so that you know how

long to run the system. This will put the nutrients at root level, where

they can be taken up most efficiently. Watering-in with more water than

¼ inch can result in fertilizer leaching more rapidly through the soil.

STEP 5 MAINTAINING A HEALTHY LAWN

roper lawn maintenance is vital for the long-term health of your

lawn. Appropriate mowing and watering practices must occur so

your lawn will have a healthy root system, be more drought-tolerant

and be able to resist pests and disease.

Ideal grass heights are:

When Mowing

•

Never remove more than

one-third of the leaf blade at

any one time. Cutting too

much of the leaf blade can

stress your lawn. If your lawn is

under any stress (shade, traffic,

drought, etc.), raise the mowing

height.

•

Mow at the highest height for

your grass species. See chart for

specific types. Mowing at lower

heights can result in a shallow

root system.

•

Keep your mower blades sharp.

A dull blade tears the grass

blades, making the grass

unattractive and prone to insect

or disease invasion.

•

Do not mow when lawn is wet.

This is dangerous for you, tough

on the mower and bad for the

grass.

•

If you miss a weekly mowing,

Credit: Florida-Fri

gement Practices

for Protection of Water Resources by the Green Industries.

raise the mower height so you

*Dwarf varieties of St. Augustine grass are the only

do not remove too much of the

cultivars of this species that should be mowed at

2-2½ inches.

grass blade. Bring the height back down to the recommended level

gradually over the next few weeks.

• Keep grass clippings, vegetative material and vegetative debris away

from storm drains, ditches, water bodies and roadways.

• Leave grass clippings on the ground. They do not contribute to thatch,

and they return nutrients and organic matter back to the lawn.

When Watering

• Irrigate around sunrise or in

the early morning hours. You

want the leaf blades to dry out

fully during the day.

• Do not apply water to just

wet the top of the soil; this

will result in a shallow root

system. Apply enough water to

encourage deeper root growth.

• In most parts of Florida,

irrigate to apply ½- ¾ inch of

water. Heavier clay soils need

only about ½ inch of water while sandy soils may need up to ¾ inch

of water.

Irrigation System Tips

More lawns are damaged by improper irrigation practices than by any

other practice. Take control of your automatic irrigation system using

these tips:

• Florida law requires that all irrigation systems have working rain

sensors to override the system when enough rain has fallen. Check

your rain sensor to see if it’s installed correctly and still working.

• Sprinkler heads are easily misaligned or broken, which can lead to

improper water application to your lawn and may waste water as

runoff. Inspect your irrigation system regularly.

• To find out how long you need to run your irrigation system, perform

a catch-can test (p. 10). If applying these amounts causes runoff,

reduce the amount of water applied. In some soils it may be necessary

to first apply half the amount needed, let it percolate through the soil,

and then apply the remaining water a short time later.

• Turn your system to the “off” or “manual” position. Water only when

leaf blades start to fold in half lengthwise or when footprints remain

visible for a few minutes. Irrigate when about 30 percent of the lawn

shows these signs, unless rain is forecast in the next 24 hours.

Seasonal Watering Tips

Regardless of the season, grass needs no more than ½ to ¾ inch

of water each time you irrigate. Irrigation frequency will vary by

location, soil type, amount of shade, temperature and other lawn

characteristics and stresses.

In the winter months, grass growth is less active and may need

•

to be watered every 10 to 14 days. Overwatering in the winter

can encourage pests and disease in your lawn.

In the summer months, grass growth is more active and

•

may need to be watered every 2 to 3 days. However, normal

summer rainfall often supplies enough water, so you can

operate your irrigation system manually and wait to turn it on

as needed.

Resources

For more information on Florida-friendly fertilizing, contact your local

Florida-Friendly Landscaping™ coordinator.

Charlotte County

Marion County

25550 Harbor View Road, Suite 3

2232 N.E. Jacksonville Road

Port Charlotte, FL 33980

Ocala, FL 34470-3615

(941) 764-4340

(352) 671-8412

Citrus County

Pasco County

3650 West Sovereign Path, Suite 1

36702 SR 52

Lecanto, FL 34461

Dade City, FL 33525-5198

(352) 527-5700

(727) 847-8177

Hernando County

Pinellas County

21030 Cortez Blvd.

12520 Ulmerton Road

Brooksville, FL 34601

Largo, FL 33774-3695

(352) 540-6230

(727) 582-2108

Hillsborough County

Polk County

5339 S. CR 579

P. O. Box 9005, Drawer HS03

Seffner, FL 33584-3334

1702 Hwy. 17-98 South

(813) 744-5519

Bartow, FL 33831-9005

(863) 519-8677

Levy County

625 N. Hathaway Avenue, Alt. 27

Sarasota County

Bronson, FL 32621

6700 Clark Road

(352) 486-5131

Twin Lakes Park

Sarasota, FL 34241

Manatee County

(941) 861-5000

1303 17th Street West

Palmetto, FL 34221

Sumter County

(941) 722-4524

7620 SR 471, Suite 2

Bushnell, FL 33513-8716

(352) 793-2728

If your county is not listed above, please contact the UF/IFAS Florida-Friendly

Landscaping™ program director at (352) 273-4520 or visit FloridaYards.org.

For more guidance on turfgrass and landscape management, contact FDEP at

(850) 245-7508 and ask for a copy of the Florida-Friendly Best Management

Practices for Protection of Water Resources by the Green Industries.

Glossary

catch-can test - method of

pesticide - a chemical or other

measuring the amount and even

substance used to prevent, destroy

distribution of water applied to a

or repel pests

lawn by an irrigation system

phosphorus - an element essential

chelated - compounds existing

for plant growth that promotes

in a form that serves to make

flowering and cellular functioning;

micronutrients available for

however, excessive amounts can lead

absorption by plants

to water pollution

dormant - not actively growing

pollutants - substances that make

the soil, water or air harmful or

drought-tolerant - describes plants

generally unusable

that require less water because

potassium - an element essential

they are adapted to regions with

to plant growth that promotes root

frequent drought or to soils with

development and stress tolerance

low water-holding capacity

runoff - excess water that flows

impervious - resistant to

across surfaces rather than soaking

penetration by fluids or roots

in; eventually enters a water body;

may pick up and carry a variety of

leach - the movement of water

pollutants

soluble substances downward

through the soil

slow-release fertilizer - fertilizer

that releases its nutrients slowly over

nitrogen - an element essential

a long period of time

for plant and vegetative growth;

however, excessive amounts can

soluble - capable of being dissolved

lead to water pollution

thatch - a layer of dead and living

nutrients - chemical elements

plant matter that accumulates

and compounds found in the

between soil and green leaf tissue

environment that plants and

in grass, often blocking water and

animals need to grow and survive

nutrient movement into soil

percolate - to cause water or

another liquid to pass through a

porous material or small holes

Balancing Water Needs ... Protecting Water Resources

Contributors and Reviewers:

Esen Momol, Ph.D., Director of Florida-Friendly LandscapingTM, and Laurie

Trenholm, Ph.D., Associate Professor and Turf Specialist

The Southwest Florida Water Management District (District) does not discriminate on the basis of disability. This nondiscrimination

policy involves every aspect of the District’s functions, including access to and participation in the District’s programs and activities.

Anyone requiring reasonable accommodation as provided for in the Americans with Disabilities Act should contact the District’s Human

Resources Director, 2379 Broad St., Brooksville, FL 34604-6899; telephone (352) 796-7211 or 1-800-423-1476 (FL only), ext. 4702; TDD

1-800-231-6103 (FL only); or email ADACoordinator@WaterMatters.org.

VISPT 10-10