Botanically called Digitaria ciliaris, Southern crabgrass is not a grass, but actually an invasive weed that comprises several stalks with tendrils that spread along the surface of the ground. It grows in different locations in southern United States and Mexico, hence the name "southern." This noxious weed grows quickly, feeding on water and nutrients in the soil meant for lawn grass, thus killing it in time to overtake the area. Rid your lawn of crabgrass immediately to prevent it from spreading.
Wear thick rubber gloves and pull crabgrass plants out with your hands. Grip the tendrils securely and pull them along with their roots. Dig the dirt around the plant with a hand shovel to loosen it so it comes out of the soil easily.
Follow label directions for mixing 1 oz. of spreader sticker with every gallon of pre-emergent herbicide. Spreader sticker ensures the herbicide sticks to the foliage and does not wash away in unexpected rains. Pre-emergent herbicides kill the seeds of this noxious weed, thus preventing them from germinating and spreading.
Pour enough mixture over the crabgrass plant so it reaches down to the roots.
Check the weeds every few days to determine the success of the chemical treatment. Crabgrass should turn brown and begin to wilt after five days. Spot treat every two weeks until it dies out. Rake the area to collect the dead crabgrass and discard appropriately.
Apply a post-emergent herbicide in late spring to crabgrass plants that still appear in the lawn. These herbicides do not effect seeds but kill mature weeds.