Lawn Weed Descriptions

Black Medic

• Black medic weed leaves have three leaflets with the center leaflet extended on a short stalk. It grows low to the ground with stems extending 1 to 2 feet from the crown of the plant. Its small, compact yellow flowers form in the leaf axis. Black medic is an annual broadleaf turf weed that grows as a perennial in mild climates.

Knotweed

• Knotweed adapts easily to high-traffic lawn areas and sidewalks. Its leaves are elliptical and taper to a rounded tip. Knotweed stems grow prostrate but do not root and spread at the nodes. It is distinguished by a papery sheath at the base of each leaf. Flowers are small, white and grow in each leaf axis.

Henbit

• Henbit is a common lawn weed identified by its upright square, hairy stems and pale purple, trumpet-shaped flowers. Henbit is a winter annual weed that thrives in the moist conditions of early spring. Fertilizing in early spring intensifies weed growth and causes unwanted growth flush in turf grass. Henbit sometimes grows flat to the ground and roots at the nodes.

Grabgrass and Goosegrass

• Crabgrass and goosegrass are common summer annual lawn weed grasses. Crabgrass has hairy, pale green leaves ¼ to ½ inch wide and seed heads that project like fingers at the end of each stem. Goosegrass leaves are dark green and narrower than crabgrass. Its seeds are born in straight rows on the spiked seedhead. Crabgrass germinates by seed each spring, goosegrass four weeks later and continuing through summer.

Nimblewill

• Nimblewill spreads over lawns by stolens, sometimes called runners. It is a blue-green perennial weed that forms dense patches that turn brown in the winter. Nimblewill leaf blades are 1 ½ to 2 inches long, ¼ inch wide. They taper to a sharp point on long, slender stems without nodes. Its seedheads are also long and slender. Nimblewill weeds grow and spread rapidly during warm summer months.

Yellow Nutsedge

• Sedge weeds are often described as grass-like, even though they belong to a distinctive sedge family of plants. Yellow nutsedge has erect, triangular stems that are yellow-green and shiny. Its flowering seed heads are chestnut-brown if not mowed down. Sedge prefers wet, moist parts of the lawn. It reproduces and spreads by vigorous, scaly underground rhizome. Leaves and stems die back in winter and new growth emerges from the rhizomes each spring.