Everything You Need to Know About Lawn Fertilization

Lawn fertilization is a primary contributor to the rich lawn that you love. Nitrogen is the nutrient most often associated with the deeper hues, and together with adequate levels of moisture, it can give your lawn a healthy luster.

Thick grass doesn’t just make your yard beautiful. It also helps with weed control by taking up every inch of available space, leaving no room for weeds to take root.

To reach a high lawn quality, grass needs to grow rapidly for both density and stress tolerance. Fertilizing your lawn is an essential part of that process, allowing your lawn to grow healthy and strong.

Here's a tidbit you might not know: Healthy grass serves as a kind of mini air conditioner for the surrounding area. As much as 50% of heat striking a turf area is eliminated by a plant process called “transpiration.” Hello, perfect picnics in the summer!

If your lawn has been damaged by insects, lawn disease, high temperatures, drought conditions and invasive weeds (you’ll be able to tell from discoloration, patchiness and sections of dead grass) a lawn fertilizing schedule will contribute to a rapid recovery.

Well-fertilized, healthy grass can also become more resistant to stress conditions, such as extreme weather and heavy traffic. The more nutrients your yard has, the better it can survive through these conditions. 

Proper fertilization for your lawn’s specific needs can keep it healthy in the face of rough conditions. The big question is—how do you know which lawn fertilizer is best? 

Here’s how to get started:

1. Learn the number system.

When you look at a bag of lawn fertilizer you will notice three numbers, such as 10-10-10 or 20-5-10. These numbers represent the percentages of nutrients. 

The first number is nitrogen (N), which makes grass plants grow and become greener. The second number is phosphorus (P), which stimulates root and seedling development (very important when establishing new grass), and the third number is potassium (K), which promotes tolerance against disease and drought. 

You’ll need a ratio that provides the right nutrients for your local weather conditions and issues your lawn is facing. 

2. Identify whether your grasses are cool-season, warm-season, or a mixture of the two.

Warm-season grasses turn brown after the first frost while cool-season grasses stay green all year (or nearly all year) in cool and transitional zones—but will go brown in summer in warm-season zones.

If you planted the grass yourself or are familiar with grass types in the area, you may already know what types of grass make up your lawn. 

The southern states tend to support warm-season grasses, such as bahiagrass, bermudagrass, centipedegrass, St. Augustinegrass, and zoysiagrass, while the northern ones house cool-season grasses, like Kentucky bluegrass, perennial ryegrass, tall fescue, and fine fescue. However, across the central states from coast to coast are large sections of transitional areas home to both warm and cool-season grasses.

3. Determine soil types and drainage.

Choosing the right fertilizer also depends on your soil type (something a TruGreen lawn care specialist can determine through a Healthy Lawn Analysis®.

If you have sandy soils that drain well, grasses will enjoy plenty of access to oxygen; however, nutrients can leach out with draining water and won’t remain as long in the soil. 

Clays and other poorly drained soils can actually be quite fertile, but poor drainage can still result in unhealthy grasses. Knowing your landscape will help you determine what your lawn needs to thrive.

You’ll also want to perform a soil pH test, and build this into your annual lawn care schedule. Soil pH is important to the health of grass and can affect nutrient uptake in plants or indicate a mineral deficiency in the earth. A soil pH that is too high or too low can result in inefficient use of fertilizer by turf, excess thatch buildup and increased pest problems.

You can get a simple kit from your local home improvement or garden store. The ideal pH is typically 6.5 depending on your grass type. If the number comes up lower, it is too acidic and could benefit from pH-raising additives like wood ash or lime. If it’s much higher than that, you can lower the pH with sulfur and organic compost. 

4. Choose your lawn fertilizer option.

Most fertilizers you get in stores are synthetic and come in two general categories: quick-release and slow-release. 

Quick-release granules let the nitrogen reach the soil fast, which helps the lawn green up in shorter time span. Unfortunately, this method loses a lot of the nutrients since the plants can’t utilize them all at once, which means it might look good now, but the risk for plant damage and disease is increased. 

Quick-release fertilizers are also more likely to give your yard fertilizer “burn,” leaving the grass brown and spindly.

Slow-release granules may not give your lawn that quick, green color, but they’re less likely to burn your lawn and will last longer overall. Also, you won’t need frequent applications, which will save you some labor.

Store-bought organic slow-release fertilizer can be made from grains, feather meal, and other natural sources. Patience is key: Organic fertilizers usually take longer to break down, so they might not release nutrients right away. However, that slow release makes it very difficult to harm your plants by overfertilization.

Want to go organic? You can count on a TruGreen® PhD-certified specialist to recommend environmentally responsible products as part of TruGreen’s TruNatural® Plan that provides an all-natural way to care for your lawn using 100% natural, organic fertilizer. 

For more information, watch this video.

Fertilizers, weed killers and other soil products are typically sold by the amount necessary to cover a certain square footage.  

For example, a standard bag covers 5,000 square feet.  So first determine the square footage of your lawn (exclude the square footage of the house or driveway) by multiplying the length of your lawn by its width. If you have 34,020 total square feet, divide that number by the allowance per bag to get your answer:  34,020 / 5,000 = 6.8. You’ll need roughly seven bags of lawn fertilizer.

Fertilizing your lawn might sound easy, but setting an effective fertilizing schedule can be a challenge. 

Striking the proper balance is essential for lawn health. Too much can leave fertilizer burn, and too little lawn fertilizer can leave a yard prone to weed problems and thin growth, so be sure to follow the directions on the bag or box. 

If you live in southern areas where lawns feature warm-season grasses, we recommend fertilizing your grass in the late spring or early summer, with a second application in the late summer.

We recommend fertilizing cool-season grasses in early fall for a green lawn in spring. For most regions where cool-season grasses grow, October or November are the months to apply fertilizer. A rule of thumb: Fertilize before the grass starts to change color in cooler temperatures.

Looking for help from the pros? 

For more than 35 years TruGreen® has been helping homeowners just like you achieve a lawn they love. When you sign up for a TruGreen lawn plan, you qualify for a FREE Healthy Lawn Analysis®, where a TruGreen PhD-certified specialist will explore every aspect of your lawn to determine exactly what it needs to reach its fullest potential. 

We’ll take that information and create a tailored plan for your lawn, including a lawn fertilizer schedule to help your lawn thrive. 

For more information on how to achieve a lawn you’ll love, visit TruGreen.com or call 866.688.6722 today.