Problem: Crabgrass Dying
Crabgrass (Digitaria species) is an annual grassy weed. It forms large, flat clumps, smothering lawn grass as it spreads. Crabgrass dies with the first killing frost in the fall or with the onset of cold weather, leaving dead patches in the lawn. Crabgrass sprouts from seeds in early spring.
Prevent crabgrass by keeping the lawn at least 2 1/2 inches tall. A tall, thick lawn seldom contains much crabgrass.