Crabgrass is an annual warm season grassy weed and once it takes root in your lawn, it can be difficult to kill. Use a pre-emergent herbicide in the late winter or very early spring to keep crabgrass from sprouting in your lawn. During the summer and after the crabgrass has rooted in your lawn, you can kill it by spraying the affected areas with a weed killer specifically formulated to not damage your lawn.
Mow your centipede grass lawn seven days before treating your lawn for crabgrass.
Choose a selective herbicide that has sethoxydim as its active ingredient. Sethoxydim is safe for centipede grass lawns and selectively kills crabgrass. Mix the herbicide with water in a sprayer following the manufacturer's directions.
Spray your centipede grass lawn with the herbicide when the wind blows less than 10 mph. Allow the herbicide to remain on the grass for one hour before watering. Wait seven additional days before mowing your lawn.