Testing Your Soil, and Fertilizer Types
Whether you’re growing warm-season grass like Bermuda or St. Augustine, or your lawn is filled with cool-season Kentucky bluegrass or fescue, all lawns require regular feeding throughout the year for proper nourishment and growth.
Sticking to a regular fertilization schedule, and applying the correct type and amount of fertilizer at the right time will help keep your lawn attractive and healthy year round.
Most grasses grow best in soils with a pH between 6.0 and 6.5. A soil pH below 5.5 is considered to be acidic, and anything above 7.0 indicates an alkaline soil condition.
If the pH level of your soil is below 5.5, you should consider an application of lime, and if it’s above 7.0, you likely need an application of gardener’s sulfur.
You can easily do your own soil testing with an inexpensive electronic soil tester, and many local extension services offer comprehensive soil testing for a small fee.
Today’s fertilizers come in many unique formulations designed to tackle a wide variety of lawn care needs. You’ll find fertilizers that include pre-emergents for weed control, some with insect control, starter fertilizers for newly planted lawns, and others formulated to address a host of lawn care issues.
All fertilizers contain three primary nutrients: nitrogen, phosphorus and potassium, often referred to simply as NPK.
On the label of each package of fertilizer, you’ll find three numbers prominently listed that represent the percentage by weight of each of these three major nutrients.
For example, a common type of all-purpose fertilizer is often referred to as 10-10-10. If you purchase a 50 pound bag, 5 pounds (or 10 percent) would be nitrogen, 5 pounds would be phosphorous and 5 pounds are potassium.
These nutrients each play specific and vital roles in the overall health and development of your lawn.
• Nitrogen is always the first number listed and it is the key
• Phosphorous, the middle number, is needed for the
• Potassium, the last number listed, is important for the
“Up, Down and All-Around”is another way to think about NPK and the numbering system for fertilizers. Your lawn needs nitrogen for the leaves’ color and growth, phosphorous for strong roots, and potassium for overall health.
Keep this in mind when planning your lawn care regimen for a healthier grass year round.
Granular fertilizers are available in different time-release formulations that allow you more control over how you’re feeding your lawn.
Quick-release, ammonium-based fertilizers contain a more water-soluble nitrogen that grass can easily absorb. These are designed to produce a rapid response in growth and color.
Slow-release, urea-based fertilizers are treated with sulfur- or polymer-coated nitrogen granules that the soil breaks down more slowly to feed your grass over a longer period of time. This way, less of the nutrients are lost through leeching. Another plus is that slow-release fertilizers are less likely to cause burning.
Organic fertilizers help grow a thick, green lawn naturally. They can be purchased or created at home. You can leave grass clippings or mulched leaves on the lawn after mowing. As they break down, they release nutrients back into the soil.
Or you can use granular organic fertilizers. They’re made up of grains such as ground corn, alfalfa, cottonseed or soy as well as blood and feather meal. The primary advantage of organic fertilizers is their slow release of nitrogen and other fertilizer elements. That means a lower chance of leeching or burning.
Here’s something else to consider when shopping for lawn fertilizer.
You can reduce the cost of fertilizing by determining the total amount of fertilizer you’ll need for the season and buying that amount in the largest package available. A large package of fertilizer generally costs less per pound.
How Much and How Often Should You Fertilize?
How much and how often should you fertilize? Well, the honest answer here is, it depends – mainly on the type of grass, what kind of fertilizer you use and the amount of time you have to invest in a dedicated lawn fertilization schedule.
Let’s consider grass types in general first:
Warm-season varieties like Bermuda, zoysia, centipede and St. Augustine grow vigorously throughout much of the year and tend to be a bit more high-maintenance. These types of grasses need to be fed 3 to 4 pounds of nitrogen per 1,000 square feet of lawn per year.
If you’re using a slow-release, high-nitrogen premium lawn fertilizer, an application every 90 to 120 days — at the start of spring, summer and fall — will help keep your lawn green and healthy year round. When using all-purpose fertilizers that generally contain less nitrogen, you will want to fertilize every six to eight weeks.
Cool-season varieties, on the other hand, grow and spread more slowly and need only 1 to 2 pounds of nitrogen per 1,000 square feet each year. Fescue, Kentucky bluegrass and rye are all examples of cool-season grasses. And, since cool-season grasses tend to be semi-dormant during the summer, you could probably get away with fertilizing only in the spring and fall.
So when is the best time to fertilize your lawn?
Believe it or not, the correct answer is in the fall. Why? Because your grass is not only still growing, it’s also storing away nutrients and other essential elements needed to flourish come spring.
Plus, the cooler weather, warm soil, ample rain and lots of sunshine create the perfect environment for grass to develop strong roots and grass seeds to germinate.
For all these reasons, if you had to choose just one time of the year to fertilize your lawn, you’d want to do it in the fall, sometime just before or after Labor Day. An application of nitrogen-rich, slow-release fertilizer will continue to feed your lawn and provide essential nourishment for the coming spring.
And here’s a tip: Before you fertilize your lawn, check your local weather forecast. Plan to fertilize just before the forecast calls for a day of light, steady rain. You’ll save water and your grass will be well-fed.
Second only to the fall, spring is next most important time of the year to fertilize your lawn. Spring grasses come to life hungry and ready to be fed. Fertilize your lawn as soon as the dormant grass is at least 50 percent green again.
Use quick-release weed and feed fertilizer to eliminate unsightly weeds without harming your grass. They provide all of the benefits of a lawn fertilizer but contain a broad-spectrum herbicide to kill weeds while not harming the grass. It’s important to always apply weed and feed to damp or wet lawns so the herbicide can easily contact the weeds and eliminate them.
Avoid using weed and feed if you plan to reseed your lawn in the same season. As a general rule, you can apply weed and feed in the spring and overseed in the fall and be safe.
Summer is hard on lawns. The heat, drought, insects and increased traffic can really take their toll on your lawn during the summer months. Feeding your lawn with an application of slow-release fertilizer at the start of summer will help keep your grass healthy and green throughout the season. And if insects are a problem in your yard, be sure to use one of the many fertilizers available with insect control.
But, if your lawn is of the cool-season variety, you may not need to fertilize. Since cool-season grasses are semi-dormant in summer, you may end up feeding more weeds than grass.
There are several methods you can use to apply fertilizer depending on the type of fertilizer you’re spreading, the size of your lawn and your personal preference.
Whichever spreader you choose, applying the right fertilizer at the correct rate is important to prevent the appearance of patchiness and discoloration in your lawn. You’ll find recommendations for the proper spreader settings on the label of most fertilizers.
• Walk-behind broadcast spreaders are the most popular
• Small handheld broadcast spreaders are also handy for
• Convenient walk-behind snap feeders have also become
• Drop spreaders work in much the same way as broadcast
• Liquid spreaders spray fertilizer from a bottle affixed to
Here’s a tip: For better coverage and uniformity, apply fertilizer in overlapping patterns. Make one complete pass vertically across your lawn and a second pass horizontally to ensure an even dispersal for fertilizer over the entire lawn.
You’ll want to fertilize only when the grass is dry to reduce the possibility of leaf burn. But don’t forget to water your lawn thoroughly after fertilizing so that the nutrients soak into the soil.
Last but not least, make sure to clean your spreader before putting it away. That way, it’s ready for use the next time you need to feed your lawn.
Cool season (Northern climates)
Fescue, Kentucky Bluegrass and Rye
|Spring, summer, fall and winter||Approximately 2 lbs. of nitrogen per 1,000 square feet*||• Use a fertilizer with crabgrass control
for early spring application
• Use a fertilizer with broadleaf weed
control in late spring
• Use a fertilizer with insect control in
• Use a winterizer fertilizer during the fall
• Water thoroughly after spreading,
depending on product used; do not
water with the broadleaf weed control
fertilizer for 24-48 hours after product
Warm season (Southern climates)
Bermuda, Zoysia, Centipede and St. Augustine
|Spring, fall||Approximately 2 to 4 lbs. nitrogen per 1,000 square feet*||• Fertilize soon after lawn becomes green
in the spring and danger of frost has
• Fertilize again during early fall
• Use less nitrogen during the fall growing
• Use larger amounts of nitrogen in early
to late spring
• Use weed control products in mid- to late
spring, as necessary.
• Water thoroughly after spreading