fertilize lawn

Angie's How To Fertilize the Lawn

Date Published: Sept. 18, 2014

Time: 60 Minutes

Different turfs require different levels of fertilizer at different times of the year. If your goal is a lush expanse of emerald green grass, knowing what nutrients to give it and when will help you succeed. Here’s what you need to know, step-by-step:

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Tools & Materials Needed 
Soil testing kit
Fertilizer (type depends on soil test results)
Drop spreader or broadcast spreader
1Identify your grass type

Warm season grasses grow primarily in the South and turn brown in the fall after the first frost. The best time to fertilize warm season grass (such as Bermuda, Carpetgrass and St. Augustine) is summer.

Cool season grasses, which include bluegrass, ryegrass and fine fescue, grow in the northern parts of the U.S., and stay green year-round. For optimum health, these grasses need fertilization in early spring and possibly twice in the fall — once in mid-September with a high nitrogen fertilizer to strengthen blade growth and again in November with a high phosphorus fertilizer to promote root growth.


Both warm and cool season grasses can thrive throughout the middle of the country. If you’re unsure what type of grass you have, start by checking with your county extension office. You can also ask a lawn care professional, or take a sample of turf to a nearby garden center.

2Test the soil

Before applying anything to the lawn, test the soil to find out what it needs. “You want to carefully plan what fertilizer you are giving your turf,” says Brian Schmauder, maintenance operations manager of highly rated Cutting Edge Lawn & Landscaping in Alexandria, Virginia. “Otherwise you may be wasting your time, money, and creating a runoff situation leading to pollution in our waterways.”


You can buy pH testing kits for soil at garden centers or online, with the average cost ranging between $11 and $20. The results of the test will tell you the alkalinity and acidity of the soil, and help determine what pH your fertilizer should have in order to balance the soil’s composition.

3Select a fertilizer

With your lawn’s dimensions in hand, along with the results of your soil’s pH test, head to a garden center or hardware store to purchase fertilizer. Read the labels on the fertilizer bags carefully to make sure they’re compatible with your grass type. Also pay attention to the three-digit formula code (often called NPK) on the bag, which tells you how much nitrogen (N), phosphorus (P), and potassium (K) the mix contains.

For example, a bag marked 16-4-8 contains 16 percent nitrogen, 4 percent phosphorous and 8 percent potassium. “Check your soil sample to make sure that your turf even needs that much nitrogen,” Schmauder says. “Most homeowners don’t know that you can damage your turf with too much fertilizer.”

4Apply the fertilizer

Using the proper equipment can make a difference in the results of your lawn fertilization. If you have a large lawn, you may need to rent equipment designated to spread the fertilizer evenly throughout the yard.

“Drop spreaders provide targeted applications,” says Steve Heiner, owner of highly rated Grass Masters in Lumberton, New Jersey. “Broadcast spreaders are much easier for the average person to use, and are considerably faster.”

However if you’re not comfortable with the application process, hire someone who is. “Please call a professional who is equipped with the proper tools,” Schmauder recommends. “Fertilizer is dangerous to you, your pets, wildlife and your landscape. If you don’t know what you’re doing, ask!”

5Water the lawn

Watering after fertilization is important. “Fertilizer should be watered thoroughly to move the product down to the roots where the plant can take it in,” Heiner advises. “A good 30- to 45-minute soaking will do.”

If rain is forecasted in the near future, that will suffice. However, if kids or pets will use the lawn soon after treatment or temperatures are above 85 degrees (which can increase the chances of fertilizer burning the lawn), water the lawn shortly after fertilizing.