Centipede grass infesting Zoysia lawn

Q: I have an infestation of centipede in my Meyers zoysia lawn. During the dormant season, it readily shows up as much darker than the dormant zoysia. Is it OK to spray the dormant centipede with Roundup without harming the dormant zoysia?

A: I doubt you have centipede grass. In the winter, zoysia is completely brown and centipede a very light greenish yellow. I’ll bet you have carpetgrass, which looks very much like centipede in the summer. That’s bad news because carpetgrass is very hard to control with older chemicals. It’s a good thing herbicide research is ongoing.

I haven’t used it but the label for Celsius WG indicates that it will control broadleaf carpetgrass, Axonopus compressus, and is safe to use on zoysia. Do your own research; read and follow the label exactly. This herbicide is comparatively expensive, but you can save money by using the single-use packages. Note that it only covers 2,000 square feet at the rate you’ll use. While you’re shopping, get some non-ionic surfactant. When mixed with herbicide, it helps the chemical(s) be absorbed by the weed leaves.

Changing the environment of your lawn can be of use too. Keep your lawn on the dry side, fertilize appropriately for zoysia grass, and raise the pH based on a soil test, georgiasoiltest.com.