Q: I am having some difficulty keeping my centipedegrass healthy. What should I do?
Q: I am having some difficulty keeping my centipedegrass healthy. I have been using a common fertilizer found at any of the garden centers but a friend told me to call you because I might be over doing it. I fertilized in the late winter, then again in the spring and I am about to fertilize again. What should I use? I have also used a weed killer which contains the active ingredient 2,4-D.
A: Centipedegrass requires very little nitrogen therefore the fertilizer you are currently using is too high in nitrogen compared to the amount of potassium. We would recommend a configuration of 15-0-15. Remember the configuration is listed in the order of nitrogen first, phosphorus second and potassium last.
It would be prudent to apply nitrogen in the formulation of nitrogen sulfate for centipedegrass as this grass prefers a more acid soil between 5.5 and 6.5. The sulfur compound in nitrogen sulfate will help lower the soil pH on a temporary basis which will enable centipedegrass to absorb the nutrients. Consider fertilizing centipedegrass only twice a year, spring and fall. Centipedegrass will never be as dark green as the standard St. Augustinegrass so do not try to over fertilize to produce the dark green color.
It is possible a portion of the damage to your lawn may have been caused by the weed killer. Some herbicide labels containing 2,4-D indicates the product should not be used on certain cultivars of St. Augustinegrass or centipedegrass. Therefore, it is possible the damage on your lawn may have been caused by the combination of herbicide and the application of the high nitrogen from the fertilizer.