A weed with 1/2-inch-long, teardrop-shape leaves and starlike white flowers grows in thin spaces in the lawn. The stems have white hairs on one side and root easily at their joints. Common chickweed grows primarily in damp, shady areas under trees and shrubs and on the north side of buildings, but it can also occur in dormant warm-season grasses. The weed invades lawns when they begin to thin out from insects, disease, mechanical damage, or shade. It has a low prostrate growing habit, forming a dense mat that crowds out the grass.
Treat the lawn when the plant is growing actively in the early spring or late fall. Repeated applications may be necessary.