Crabgrass is an annual weed of the grass family. With more than 300 species, crabgrass is a rapidly growing grass with a germination period that lasts from January to June. Crabgrass will tolerate hot, dry soil and can easily survive droughts. Because of its resilience, crabgrass can be a pesky problem that is very difficult to eliminate.
Crabgrass growth is best controlled by maintaining a healthy, dense turf of desired grass. Mow your law at 2.5 to 3 inches and mow frequently, at least twice per week in the spring and bi-weekly during the summer.
Water your lawn in a manner that ensures the grass roots receive moisture, not just the blades. Watering should be infrequent--only when the grass begins to show signs of drought stress.
Fertilize your lawn with 2 to 4 pounds of nitrogen fertilizer per 1,000 square feet. Complete this process once in the late fall and again in the early winter. Do not fertilize during the summer months; this can increase the rigidity and growth of your crabgrass.
If your lawn is dense but still does not reduce the growth of crabgrass, consider herbicides.
Pre-emergence herbicides are designed to control and kill crabgrass before it begins to grow. These chemicals should be used in early spring, long before the crabgrass and flowers emerge. If you choose a chemical that feeds the turf while weeding the crabgrass (weed and feed), choose a product that releases the nitrogen in a slow-release manner for better results.
Post-emergence herbicides are available but should be applied by a professional. These products are very difficult to mix, use and apply. Always choose a herbicide that compliments your desired grass.
Pulling crabgrass by hand is an effective way to remove it from your lawn and prevent further spread. Remove the crabgrass as soon as you spot it. Water the crabgrass area heavily before removing it from the soil. This will help to loosen the dirt, making it easier to remove the entire root. The entire root must be removed; crabgrass needs only a small root to regenerate.
Apply much on the area after removing the patch. The mulching process helps prevent roots from developing new patches.
Crabgrass is a diligent weed and may become impossible to remove entirely. Fortunately, crabgrass will die during the winter. Apply pre-emergence chemicals in the early spring to prevent a new occurrence.