What kills weeds in centipede grass depends on the type of weed and the time of year. Pre-emergent products stop weeds before they sprout in spring. Post-emergent sprays knock out weeds that already took root in your lawn. You need both tools in your plan, but product choice matters more here than with any other grass type.
I learned this the hard way when I sprayed a common broadleaf weed killer on my centipede lawn without reading the label first. The weeds died, but so did a 4-foot circle of my grass around each spot I treated. That mistake taught me that centipede grass is far more sensitive to herbicides than bermuda or zoysia. Now I always check labels twice before spraying anything on this turf.
Your centipede grass weed control plan should start with the lawn itself. A thick, healthy stand of centipede grass blocks most weeds from getting a foothold. Mow at 1-2 inches, water 1 inch per week, and keep your soil pH between 4.5 and 6.0. These basics do more to prevent weeds than any bottle of spray ever will.
For weeds that still push through, safe herbicides for centipede grass fall into two groups. Pre-emergent products go down before weed seeds pop up. Post-emergent sprays target weeds you can already see growing in your yard. Timing and product choice make all the difference between killing weeds and killing your grass.
Clemson Extension says to apply your pre-emergent between mid-February and mid-March. Get it down before soil temps hit 55°F (13°C). This window catches crabgrass and goosegrass before they sprout. Miss this window and you lose your best shot at stopping summer weeds. For broadleaf weeds like clover and dandelions, 2,4-D works well when you apply it in spring at the label rate.
Winter weeds need a different approach. Atrazine and simazine work well for annual bluegrass and henbit that pop up in fall and winter. Apply these in October or November before the weeds get established. I use atrazine on my own lawn every fall and it keeps the winter weed pressure down to almost nothing by the time spring rolls around.
Always spot-treat instead of blanket spraying your whole yard when you can. This approach uses less product and reduces the risk of harming your centipede grass. Mix your spray at the lowest label rate and test a small area first. Wait 7-10 days to check for damage before treating the rest of your lawn. Your patience will save you from burning patches in your turf that take months to grow back.
Read the full article: Centipede Grass Care and Growing Guide
