One of the most common grasses around Lancaster is centipede. Centipede’s popularity is due in large part to its reputation as a low maintenance lawn. I frequently get the question, “How much fertilizer do I need to put on my lawn?” My answer to this question, with respect to centipede in particular, is always to get a soil test. There is a much greater chance of over fertilizing centipede and sending it into a state of decline than with other lawn grasses. Centipede grows under different soil conditions than other grasses. These conditions allows this slow growing grass to better compete with weeds for space in your lawn. In fact, centipede performs best in soil conditions that can be considered poor for most lawn grasses.
The nitrogen (N) requirement for centipede is very low. Dr. Bert McCarty, Clemson University Turf Specialist, recommends no more than a half-pound of nitrogen per 1000 square feet annually, compared to standard recommendations for warm season grasses that range from three to five pounds of nitrogen per 1000 square feet.
A small amount of excess nitrogen does not directly affect centipede negatively but rather selects faster growing weeds. Higher rates of nitrogen can lead to chlorosis (yellowing), burning of the leaves and can make centipede more susceptible to winter injury.
Centipede performs best in low to medium soil phosphorous (P) levels. Soil retains phosphorous well. If you do not collect grass clippings from your lawn, there is no need to repeat yearly applications of phosphorus when soil levels are already adequate. Excess phosphorous can contribute directly to chlorotic (yellowing) by preventing proper iron availability and is considered by some experts to be a primary reason for centipede decline.
Potassium (K) is a nutrient that can benefit centipede by helping increase winter hardiness. Centipede is especially susceptible to winter injury when there are large fluctuations in temperatures during the winter. It takes centipede 10 days of cold weather to harden enough to handle freezing temperatures, while only two days of warm weather can erase any built up cold hardiness. Potassium is generally recommended in equal amounts to nitrogen when applied in the spring.
Never add any lime to centipede without direct indications from a soil test. Centipede performs best at a more acid pH range of 5.5 to 6.0. At this pH, centipede can better compete for nutrients than others lawn grasses and weeds. Soil pH is a measure of acidity. Most lawn grasses and weeds require a pH of 6.0 to 6.5.
It is important to remember that centipede is a low maintenance grass. Unless your soil test recommends something different, centipede can perform very well with little to no fertilizer or lime. A good general fertilizer for centipede is one that has about the same amount of potassium (K) as nitrogen (N) with low levels of phosphorous (P). Keep in mind, there is no substitute for a soil test.
Once you have corrected your soil nutrients, centipede does grow slowly and it will take longer to fill in. In the right soil conditions centipede can out-compete and choke out the best of weeds over time. Have patience, and enjoy your low-maintenance centipede lawn.