Centipedegrass is a warm season grass. It does its productive growth between April and September. For this reason, fertilizer applications should be done in the late spring, after green-up and in mid summer.
The amount of fertilizer to apply should be determined by a soil test (1-800-ASKUGA-1). If you have not had your soil tested, here are some rule-of-thumb recommendations for centipedegrass fertilization.
First, if the lawn has not been limed in the last few years, the soil is probably acid. You can apply 25 pounds of lime per 1000 square feet in the fall or spring. A soil test might determine that you need more – but this is a moderate amount, which is certainly better than nothing.
Although centipedegrass will tolerate acid soil, liming it up to pH 6.0 will help it look its best.
Fertilizer should be applied twice, with only 1/2 to 1 pound of nitrogen each time. The first application of fertilizer should be during or after spring greenup and then again in mid summer. Do not apply fertilizer in fall.
To determine what is 1/2 pound of nitrogen, divide the first number on your fertilizer bag into 50. The result is the number of pounds of the product that contains 1/2 pound of nitrogen.
A yellow appearance in early summer may indicate an iron deficiency due to soil temperatures lagging behind air temperatures. Spraying with iron (ferrous) sulfate (2 ounces in 3 to 5 gallons of water per 1,000 square feet) or a chelated iron source will help to enhance color.
There are many different brands of lawn fertilizer. Centipede lawns will do fine with a generic analysis of fertilizer such as 16-4-8. 16-4-8 fertilizer should be applied at a rate of 4 pounds per 1000 square feet each time. One can also use 15-0-15 centipedegrass fertilizer at a rate of 5 pounds per 1000 square feet.
Cyclone spreaders and drop spreaders can do a good job. Make sure the spreader is set properly to apply the right amount of fertilizer. It is best to apply half of the fertilizer going back and forth on the lawn and the other half while traveling at right angles to the first trip. This will give even coverage so you do not get streaks of yellow and green in the lawn.
BEST FERTILIZER? A confusing array of fertilizer brands awaits homeowners at the garden center. Fortunately, grass cannot read the advertisements! Fertilizer bags with similar nutrient numbers will perform much the same. For instance, 30-3-9 fertilizer will perform much like 29-3-4. In general, look at the first number on the bag (Nitrogen) to compare value between brands.
Q: When I go to a garden center to buy lawn fertilizer, there are several different brands. All of them have different fertilizer numbers on the bag but they all claim to be better than the rest. What is the best fertilizer for a lawn?
A: It’s a good thing your lawn grass can’t read fertilizer bag labels. Confused grass turns yellow and dies no matter what you do for it! It makes little difference which fertilizer you buy as long as it is labeled for use on a lawn. Occasionally there is a reason to use a specific analysis, such as 15-0-15 on centipede grass. For fescue, Bermuda and zoysia grass, if the numbers on the bag are similar, make your decision based on price. The better brands are formulated to have some percentage of “slow release” nitrogen.