Crabgrass (Large Crabgrass / Hairy Crabgrass)
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Invasive/Weed Grass, Erosion Control (unintentional)
Variety / Cultivar
Common Wild Type
Hardiness Zones
USDA Zones 2-11 (as an annual); sensitive to frost but seeds are extremely winter-hardy and remain viable for years.
About This Grass
A low-growing, spreading summer annual that forms a star-shaped clump or coarse mat. Light green to yellowish-green in color, it develops a thick texture as it matures. Seed heads are digital (finger-like) spikes emerging from the stem apex.
Blade Characteristics
Coarse blades (>4mm wide), flat, with a sharp-pointed tip. Color is typically pale green. Vernation is rolled in the bud. Ligule is membranous and tall with jagged edges; auricles are absent. Stems are often hairy at the base.
Root System
Fibrous and shallow, but highlighly efficient. It spreads by rooting at the joints (nodes) of the lower stems. It is quick to establish but dies off completely after the first hard frost.
Growing Information
Origin Region
Europe and Asia; now cosmopolitan and naturalized globally
Growth Habit
Prostrate, decumbent, or spreading via rooting at the nodes (stolon-like habit)
Sunlight & Water Needs
Full Sun (thrives in heat); moderate water needs but highly drought tolerant once established; adapts to various soil pH and compacted soils.
Mowing & Maintenance
Maintenance is usually aimed at eradication. Low mowing heights (under 2 inches) actually encourage its spread by opening the canopy. Does not require fertilization as it scavenges nutrients from surrounding turf.
Special Characteristics
Excellent traffic tolerance and heat resistance; highly invasive in manicured lawns; seeds prolifically; recovers rapidly from drought via seed bank.
Ecological Information
Introduced/Invasive in most turf settings. Seeds provide food for small birds and rodents. Its presence often indicates thin turf, soil compaction, or improper mowing heights in the surrounding desirable grass.