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.

Types of Lawn Fertilizer

Liquid and Granular

Fertilizer is available in two main types - liquid and granular. Choose the one that meets your lawn's needs in the form that is easiest for you to use.

• Liquid fertilizers are fast-acting. Since they are quickly absorbed, they require application every 2-3 weeks. Most are mixed with water prior to application with a garden hose attachment.
• Granular fertilizers are applied with a spreader and must be watered into the grass. Granular fertilizers are easier to control because you can actually see how much fertilizer you are using and where it is being dispersed.

Granular fertilizers are produced in two different formulations, quick-release and slow-release.

Quick-Release and Slow-Release Fertilizer

Quick-release fertilizer typically lasts for three to four weeks, depending upon the temperature and the amount of rainfall. For general use, these water-soluble nitrogen fertilizers (WSN) are also known as commodity or field grade fertilizers.

There are two main types of slow-release fertilizers, known as water-insoluble nitrogen (WIN), available for specific applications.

• Sulfur coated, which lasts for about 8 weeks.
• Polymer coated, lasting about 12 weeks.

Both time estimates may vary depending upon the amount of rainfall. To avoid unwanted growth stimulation, do not apply slow-release fertilizer late in the growing season.

Weed and Feed

Weed and Feed is a common term which refers to fertilizer that contains weed killer for broadleaf weeds such as dandelions.

• Pre-emergents, such as those commonly used to prevent crabgrass, are weed killers which must be applied before the weeds germinate. They are ineffective if the weeds are already actively growing. Pre-emergent weed killers are often mixed with fertilizer and are designed to be spread in early spring. Crabgrass normally germinates when the ground temperature reaches 60° F - the ground temperature at which dogwood trees start to bud and forsythias begin blooming.
• The weed killer in post-emergent types of fertilizers are contact killers, and are effective only if the weeds are already actively growing. They will not kill weeds which have not yet germinated.

Timing of the application of pre-and post-emergents is critical for success. Applying these products too early or too late is essentially a waste of time. Read the package carefully before selecting to be sure which product fits your needs.

Organic Fertilizer

Organic fertilizer is an alternative to traditional types of fertilizer that is more environmentally friendly. Like traditional fertilizers, organic fertilizer is available in several forms, including granular fertilizer and liquid fertilizer.

For the most ecofriendly option, choose an organic fertilizer that is made from ingredients that are both renewable and sustainable. This includes fertilizer made from alfalfa meal, cottonseed meal, and corn gluten meal.

Another organic alternative to fertilizer is compost or composted manure.

How to Read a Fertilizer Package Label

The three numbers (often called NPK) on a fertilizer package tell you the percentage of the base elements nutrient makeup by weight. These percentages in fertilizer compounds are formulated for everything from asparagus to zinnias. The three main components are:

• Nitrogen (symbol N) for leaf development and vivid green color.
• Phosphorous (symbol P) for root growth.
• Potassium (symbol K) for root development and disease resistance.

For example, a bag marked "16-4-8" contains 16 percent nitrogen, 4 percent phosphorous and 8 percent potassium.

The other 72 percent is usually inert filler material, such as clay pellets or granular limestone.

To know how much of each is in the bag, multiply the percentage by the size (weight) of the bag. (Example: a 50 lb. bag of 10-10-10 contains 5 pounds each of nitrogen, phosphorus and potassium.)

There may also be secondary elements such as calcium for root growth, magnesium for sugar formation, and sulfur for green color. The minor elements that may be present are zinc, iron, manganese, copper, molybdenum and boron.

Don't feel concerned or cheated by the presence of the so-called inert material in the fertilizer bag. Its purpose is to help distribute the fertilizer evenly and prevent chemical burn.

Preparing the Lawn for Fertilizing

Step #1 - 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. pH 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 fertilizer 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

The fertilizer package will tell you how many square feet of coverage it contains. Determine the square footage of lawn to be fertilized. Fertilizers, weed-killers and other soil amendments are typically sold by the amount necessary to cover a certain square footage. Determine this figure 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:

34,020 divided by 5000 sq. ft. per bag equals 6.8 or roughly 7 bags of fertilizer.

Proper Fertilizer Application

Fertilizing Cool-Season Grasses

Fertilize heavily in the fall, lightly (or not at all) 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.

In fall, fertilize when the intense heat of the summer has subsided. Time your fertilization so the fertilizer will become ineffective before the onset of severe cold weather. Fall is the favorite time of year for cool season grasses, so care for these types is most important at this time of year. 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.

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.

Begin fertilizing in late spring when the lawn begins to show signs of life. 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 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 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 criss-cross manner.
5. Clean the spreader thoroughly after use.

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.