Large Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Native/Wild type (No specific cultivar identified)
Hardiness Zones
USDA Zones 2-11; dies back completely after the first hard frost of autumn. It thrives in high heat and humidity during summer months.
About This Grass
A coarse, light-green to medium-green annual weed. It grows in a spreading, star-like pattern from a central crown. Stems are decumbent (laying on ground) and can grow 6-24 inches if not mowed. The seed heads are terminal racemes (finger-like) typically consisting of 3-7 spikes.
Blade Characteristics
Coarse width (5-10mm), flat shape, pointed tip, light green color, rolled vernation. Blades and sheaths are typically hairy (pubescent). The ligule is membranous and relatively tall (reaching 2mm), and auricles are absent.
Root System
Shallow, fibrous root system. It establishes extremely fast in disturbed or bare soil and can root at nodes that touch the ground, allowing it to compete aggressively for moisture.
Growing Information
Origin Region
Europe and North Africa; now cosmopolitan and naturalized throughout the United States and Canada.
Growth Habit
Prostrate, clump-forming bunch type that also spreads via stolon-like rooting at the lower stem nodes.
Sunlight & Water Needs
Full sun preferred (very shade intolerant); thrives in diverse water conditions but is extremely drought tolerant once established; grows best in soil pH 5.5 to 7.0.
Mowing & Maintenance
Maintenance focused on eradication: Mowing at 2.5-3 inches may help turf shade it out, but it adapted by seeding very low to the ground. Requires pre-emergent herbicides in spring or post-emergent selective herbicides for control.
Special Characteristics
Extremely high wear tolerance; prolific seed producer (up to 150,000 seeds per plant); salt tolerant; highly competitive in thin turf; can dominate lawns in mid-summer heat.
Ecological Information
Introduced/Invasive status in North America. Seeds provide food for small birds and rodents; however, it is considered a significant agricultural and turf nuisance that displaces native species or desirable turf blends.