Large Crabgrass (Hairy Crabgrass)
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Common wild type (no specific commercial cultivar)
Hardiness Zones
USDA Zones 2-11 (as an annual); dies with hard frost but seeds are extremely cold-hardy and survive winter in the soil.
About This Grass
A coarse, opportunistic weed that forms low-growing, spreading mats. It is pale to medium green, turning purplish with first frost. Mature plants feature finger-like (digitate) seed heads radiating from the stem top.
Blade Characteristics
Coarse (6-10mm wide), flat, with a sharp-pointed tip. Blades and sheaths are distinctly hairy (pubescent). Long membranous ligule; no auricles. Rolled in the bud (vernation).
Root System
Shallow fibrous root system; secondary roots form easily at lower stem nodes (nodes touch the soil and root), leading to rapid local spread and high thatch-like density.
Growing Information
Origin Region
Europe and Asia; now naturalized worldwide in temperate and tropical regions
Growth Habit
Prostrate or decumbent bunch-type that also roots at the nodes (stoloniferous-like behavior)
Sunlight & Water Needs
Full sun preferred; high drought tolerance; thrives in disturbed soils and adapts to various pH levels but prefers moist, fertile soil.
Mowing & Maintenance
Extremely low mowing tolerance (can survive and set seed at 0.5 inches). No fertilization recommended as it is a weed. Best controlled by pre-emergent herbicides in early spring.
Special Characteristics
Extremely high traffic tolerance; phenomenal ability to crowd out desirable turf; prolific seed producer (up to 150,000 seeds per plant).
Ecological Information
Introduced species; considered a noxious weed in lawns/crops. Seeds provide food for some songbirds, but generally lacks significant ecological value in managed landscapes.