Forget the Guesswork
Get an Estimate
Estimate how much fertilizer you'll need for your lawn project with our Fertilizer Calculator.
A lush, inviting lawn is the goal of many homeowners, but your lawn needs help from you to look its best. Like any living thing, turfgrass needs nutrients to thrive, and fertilizing is a way to help it get the nutrition it needs. Selection, preparation and proper application of the right fertilizer are keys to a healthy, green 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:
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.
Granular fertilizers are produced in two different formulations, quick-release and slow-release.
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 are also known as commodity or field grade fertilizers.
Slow-release fertilizers, known as water-insoluble nitrogen, are coated to dissolve over period of weeks for more controlled feeding.
The effectiveness of both types may vary depending upon the amount of water provided by irrigation or rainfall.
Weed and Feed is a common term which refers to fertilizer that contains weed killer for broadleaf weeds such as dandelions or grassy weeds like crabgrass. Check the label to see which weeds the product will treat.
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. As with synthetic products, apply properly and with caution.
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 feather meal, bone meal, alfalfa meal, cottonseed meal or corn gluten meal. Another organic alternative to fertilizer is compost or composted manure.
The three numbers (often called NPK) on a fertilizer package tell you the percentage of the base elements and nutrient makeup by weight. These percentages in fertilizer compounds are formulated for everything from asparagus to zinnias. The three main components are:
For example, a bag marked "16-4-8" contains 16 percent nitrogen, 4 percent phosphorous and 8 percent potassium. In this case, the other 72 percent is usually inert filler material added to aid distribution by your spreader. There may also be secondary elements added such as calcium, magnesium, iron or others.
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. 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:
250 by 150 ft.
37,500 sq. ft.
80 by 36 ft.
2,880 sq. ft.
12 by 50 ft.
600 sq. ft.
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.
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.
Spraying Liquid Fertilizer
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.
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. .