Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Large Crabgrass (common wild type)
Hardiness Zones
USDA Zones 2-11 (as an annual); dies back completely after the first hard frost but persists through a prolific soil seed bank.
About This Grass
A coarse, opportunistic annual that forms low-growing, spreading mats. It is light green to medium green, turning purplish with first frosts. It produces finger-like racemes for seed heads that can produce thousands of seeds per plant.
Blade Characteristics
Coarse width (5-10mm), flat shape with a pointed tip. Light green color with a prominent midvein. Vernation is rolled in the bud. Noticeable hairs present on the leaf blade and sheath; ligule is membranous and tall; auricles are absent.
Root System
Shallow, fibrous root system. Though annual, it establishes very quickly in disturbed or thin turf areas; it does not form a permanent sod but creates dense seasonal mats that compete with desired grasses.
Growing Information
Origin Region
Native to Europe and Asia; widely naturalized throughout temperate and tropical regions of North America
Growth Habit
Prostrate, spreading decumbent bunch-type that roots at the nodes (stoloniferous-like behavior)
Sunlight & Water Needs
Full sun (requires high light to thrive); very drought tolerant once established; adapts to various soil types but prefers moist, fertile soils with a pH of 5.5-7.5.
Mowing & Maintenance
Grows faster than most turfgrasses; mowed at turf height (1-3 inches) but can survive extremely low heights; maintenance typically involves chemical pre-emergent or post-emergent control rather than cultivation.
Special Characteristics
Highly competitive in thin lawns; high heat tolerance; moderate salt tolerance; excellent ability to crowd out native or turf grasses in summer; poor shade tolerance.
Ecological Information
Introduced/Invasive in manicured landscapes. While seeds provide food for some songbirds and ground-feeding birds, it is generally considered a nuisance that reduces biodiversity in managed ecosystems.