Fertilize Your Lawn

Why Fertilize the Lawn?

Your soil supplies some of the nutrients that turfgrass needs but most soils are not able to provide all of them during the entire growing season. A healthy and actively growing lawn uses a great deal of energy. Fertilizer helps your lawn stay healthy by:

  • Promoting new leaf and root growth
  • Aiding in recovery from foot traffic and pest damage
  • Reducing and controlling weeds
  • Replacing nutrients lost to leaching, volatilization and grass clipping removal

Choosing Lawn Fertilizer

You must choose the right food if you expect a healthy, green lawn.  Where you live, what type of grass you have, what season it is – all are important factors in choosing the right type of fertilizer.

Preparing the Lawn for Fertilizing

Below are the basic steps for how to fertilize a lawn.  Timing is very important.

Step 1

Map of United States showing grass types.

Identify Your Grass Type

Identify your grass as a cool or warm season grass. A large section of the U.S. is considered transitional, which means that both warm and cool season grasses may grow in the area. If you live in this area, a clue to your grass type is the fact that warm season grasses will turn brown after the first frost. Cool season grasses will generally stay green all year long in the cool and transitional zones. They will not survive the summers in the warm season zone.

Step 2

Do a Soil Test

Determine the pH of your soil. The pH level is a measure of the alkalinity or acidity of a substance. The pH of your soil is important because it determines the ability of the grass to use the ingredients in the fertilizer. Your soil test will determine which fertilizer is best for you.

Bring your soil as close to neutral as possible to get the most benefit from the fertilizer you use. A pH range between 6.0 and 7.0 is accepted as being the best for growing quality grass.

Step 3

Determine Your Lawn Size

Fertilizers, weed-killers and other soil amendments are typically sold by the amount necessary to cover a certain square footage. The fertilizer package will tell you how many square feet of coverage it contains. Determine the square footage of lawn to be fertilized by multiplying the length of your lawn by its width. Then, subtract the square footage of the house, driveway and other areas not to be fertilized.

An example using rough measurements:

Lawn Measurement 250 by 150 ft. 37,500 sq. ft.
House Measurement 80 by 36 ft. 2880 sq. ft.
Driveway Measurement 12 by 50 ft. 600 sq. ft.
Total 34,020 sq. ft.

The most common size fertilizer bags are 5000 and 15000 – there are others. In the example above, 34,020 divided by 5000 sq. ft. per bag equals 6.8 or roughly 7 bags of fertilizer. Or, 2 bags of 15000 and one bag of 5000 sq. foot coverage.

Easy Steps for Proper Fertilizer Application

Knowing when to feed your lawn is essential. Your feeding schedule depends on the type of grass you have. In general, feeding is done when your lawn is actively growing. It takes commitment – a regular fertilizing schedule is required if you want a great-looking lawn year after year.

Fertilizing Cool-Season Grasses

Fertilize heavily in the fall and lightly in early spring. The growing season for these grasses is mainly in the cool months of spring and fall. Cool season grasses grow best when the temperature is in the range of 60 to 70° Fahrenheit.

Fall is the favorite time of year for cool season grasses, so care for these types is most important at this time of year. Fertilize when the intense heat of the summer has subsided, but well before the onset of severe cold weather. You may choose to apply a special winterizer fertilizer for the fall application. These fertilizers are specially-formulated to help protect the grass during the winter months.

In the spring, begin fertilizing early. You may use either slow- or quick-release fertilizer, but time your fertilization regimen so the fertilizer will be used up before the onset of hot summer weather when cool-season grasses often go dormant.

Fertilizing Warm-Season Grasses

Fertilize when the grass starts to turn green in spring. The growing season for these grasses, depending upon the geographic area, is during late spring and summer. Warm season grasses grow best when the temperature is in the range of 80 to 95° Fahrenheit, although they will also grow outside of this range.

Use either slow- or quick-release fertilizer, but time your fertilization regimen so the fertilizer will be used up before the onset of severe hot summer weather. Begin fertilizing again after the intense heat of the summer has subsided.

Always follow the manufacturer’s instructions when fertilizing, and ensure that you time the life of the fertilizer so it is not present at the onset of severe hot or cold temperatures. Failing to do so could damage your lawn. When fertilizing, too much is not a good thing.

Broadcasting Granules

1. Make sure the spreader and fertilizer are dry.

2. Set the rate-of-flow lever according to the setting listed on the fertilizer bag. If you have any doubts, apply too little rather than too much.

3. Close the hopper vent. Place the spreader on a hard surface and fill the hopper slowly. Wear gloves and a dust mask and be sure to keep fertilizer away from eyes and skin.

4. For complete coverage, cut the recommended application rate in half and apply evenly in a crisscross manner.

5. Clean the spreader thoroughly after use.

6. Clean up any excess fertilizer from driveways, patios, sidewalks, etc.

Spraying Liquid Fertilizer

1. Fill the sprayer canister with liquid fertilizer. Carefully attach the canister unit to the end of your garden hose.

2. Move at a steady pace to cover the entire lawn evenly. Walk slowly, spraying from side to side.

Do not apply other chemicals, such as herbicides or insecticides, at the same time as fertilizer. Leftover fertilizer does not store very well. Try to buy only enough for the season’s needs.

Fertilizer Spreaders

Broadcast spreaders (also called rotary spreaders) drop fertilizer from a hopper onto a spinning disc that disperses it over the lawn. Drop spreaders cover straight lines with little waste, but they must be used with care to avoid creating stripes.