Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
AI-generated identification · may be incorrect
Grass Category
Invasive/Weed Grass
Hardiness Zones
USDA Hardiness Zones 2 through 10 as a warm-season summer annual, killed by the first heavy frost.
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Variety / Cultivar
Wild type (smooth and large crabgrass species)
About This Grass
An annual grassy weed with a sprawling, mat-forming growth habit, typically growing 6 to 24 inches tall if allowed to mature. Color is generally light green to blue-green, turning purplish or reddish-brown with age or frost. Distinctive finger-like or crab-claw-like seed head spikes appear in late summer.
Blade Characteristics
Medium to coarse width (3-10 mm), flat, pointed tips, rolled in the bud (vernation). Has a membranous ligule, lacks auricles, and features prominent hairy surfaces on the blades and sheaths.
Root System
Fibrous and relatively shallow root system with strong ability to root at the lower stem nodes (stolons). Rapid establishment from seed in spring, high tendency to crowd out desirable turf.
Growing Information
Origin Region
Europe and temperate Asia; now globally distributed in temperate and tropical regions
Growth Habit
Stoloniferous and spreading prostrate to semi-erect, rooting at the lower nodes
Sunlight & Water Needs
Requires full sun and thrives in warm, dry soils with low fertility, though it responds aggressively to moisture and nitrogen. High drought tolerance as a seed, but actively growing plants wilt without water.
Mowing & Maintenance
Hard to control by mowing alone due to its prostrate growth habit below standard mower heights. High maintenance required to prevent seed production, pre-emergent herbicides are standard for management.
Special Characteristics
Extremely high seed production, highly invasive in thin lawns, poor wear tolerance compared to established turfgrasses, highly competitive in stressed or compacted soils.
Ecological Information
Introduced species globally considered a significant agricultural and turf weed. Provides minor seed food source for ground-feeding birds, but generally offers low overall ecological value compared to native prairie species.