Crabgrass (Large/Hairy Crabgrass)
Digitaria sanguinalis · Warm-season, Summer Annual, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Common Wild Type (Invasive weed in turf)
Hardiness Zones
Zones 3-11 (as an annual). Highly heat tolerant; dies completely after hard frost leaving bare patches in lawns.
About This Grass
An aggressive, pale-green annual weed forming dense, radiating mats. It outcompetes desirable turf by growing low to the ground. In autumn, it turns reddish-purple before dying with the first frost. Seed heads consist of 3-13 finger-like spikes.
Blade Characteristics
Coarse (5-10mm wide), flat, and pointed at the tip. Light green to lime green color. Known for heavy pubescence (hairs) on both sides of the blade and sheath. Ligule is membranous and tall; auricles are absent.
Root System
Adventitious, fibrous root system. High capacity to root at stem nodes that touch the soil, allowing a single plant to spread widely. Does not form deep permanent roots but establishes very quickly.
Growing Information
Origin Region
Native to Europe and Asia; widely naturalized across North America in temperate and tropical climates.
Growth Habit
Prostrate/Specially spreading, Bunch-type that roots at the lower nodes (decumbent habit).
Sunlight & Water Needs
Full Sun (thrives in heat and thinning turf); requires minimal water but grows explosively with summer rain. Very drought tolerant in disturbed soils.
Mowing & Maintenance
Grows lower than most mower settings; requires pre-emergent herbicide in early spring. Low mowing height (under 2 inches) actually helps it spread by reducing shade from desirable grasses.
Special Characteristics
Extremely high seed production (up to 150,000 seeds per plant). Salt tolerant and thrives in compacted, poor-quality soil where turf is weak. High traffic tolerance due to its prostrate matting.
Ecological Information
Invasive weed in lawns and agriculture. Seeds provide food for small birds (finches, sparrows), but it is generally considered a nuisance that reduces biodiversity in managed landscapes.