Scientific NameDigitaria sanguinalis
Other Common Names:
Synonyms (former Scientific Names):
Large crabgrass germinates in the spring and competes with turf during the summer months. Crabgrass begins germinating when sustained soil temperatures are 55 degrees F and moisture is available. In Virginia (USA) plants usually begin germinating mid April to early May in the mountains, late March to late April in the piedmont, and early March to mid April on the coastal plain. Plants compete with turfgrass during the summer, set seed in the fall, and die with first frost.
Large crabgrass leaves are densely hairy on both surfaces. Hairs are long but stiff and erect. The collar area and stems are hairy and the ligule is a large membrane. Stems tend to trail along the ground and root at nodes.
Fat cotyledon (seed leaf), hairy on all leaves and stems, large membraneous ligule and three to five-branched seedhead on slender stalk.
Flower Seed Head
Seedheads are borne on slender stalks and consists of three to five spikelets in an open arrangement.
Seeds are flat and narrow; about 1.5 mm wide and 5 mm long.
Large crabgrass is widely distributed and one of the most economically important weeds of turfgrass. Plants can be found in the lawn, under close cut such as a putting green, and in tilled areas such as a home garden.
Leaf Hair on Upper Surface
hairs from base to tip
rolled in bud
Mature Leaf Width
less than 5 mm,
6 to 15 mm
flat or oval
less than 1 mm,