Native to southern China, centipede grass is grown in the southern United States as a thick-growing, dark-colored grass. Broad-leaf weeds especially can easily crowd out and steal nutrients from this grass. By identifying the weeds that are attacking your plants, you are taking the first step in choosing the herbicide that is right for you.
Before you can use a weed killer on your centipede lawn, you need to know which kinds of weeds are plaguing your grass so you may choose the variety of weed killer that will meet your needs. The main types of weeds to look out for are broad leaf, which have wide leaf blades and usually colorful flowers; grassy weeds with round-tip stems; and sedges whose stems point out triangularly at the tip. You will need to purchase a selective herbicide that will kill these specific weeds so you can leave the rest of your healthy centipede grass without any herbicidal damage.
When purchasing your selective herbicide, you will need to choose between pre-emergent and post-emergent herbicides. Pre-emergent herbicides kill weeds before they break the surface by making it impossible for the seeds to complete their germination process. These herbicides are not effective against weeds that have already developed past this stage, which will need to be removed manually from the lawn, and must be mixed into the soil to avoid losing chemicals to runoff. Post-emergent herbicides destroy the leaf surface of the weeds on contact but are harder to purchase selectively. Gardeners should be sure to know which variety will work best for them and use all chemicals as specified on the manufacturer's guidelines.
Centipede grass when grown properly is a thick, dark-green grass that will help crowd out weeds when properly cared for. It requires a complete fertilizer with three parts nitrogen, one part phosphorous and two parts potassium. Nutrient-deprived grasses will have weak root systems and will leave bare spots in the yard where weeds can take root. These weeds can create a layer of thatch that will become a breeding ground for deadly varieties of weeds. Gardeners should avoid over-feeding or over-watering their grasses and remove all signs of weed growth as often as possible.
Liquid vs Granular
Granular herbicides are slow-releasing chemicals that give gardeners better control over killing the weeds in their lawn. They require more effort to apply than liquid herbicides, but don't usually require as much maintenance. A liquid herbicide should be sprayed only on dry, windless days in the areas where it is needed. Pre-emergent varieties should be mixed well with the soil when applied. Be careful of chemical runoff that can hurt nearby grasses and ornamental plants.
Pre-emergent vs Post-emergent
Gardeners should be very careful of mixing together various pesticides that are needed for the care of their lawns. Herbicides should not be mixed with insecticides or fungicides unless it is specifically stated that it is safe to do so. Improper use of chemicals can damage the nearby environment and leave lawns far more vulnerable to all pest threats. Follow all manufacturer instructions when applying any type of pesticide, and contact the company or local law enforcement if you have any concerns about the environmental safety of your local area.