Large Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Wild type (no specific named cultivars)
Hardiness Zones
Thrives across USDA Hardiness Zones 3-10, sensitive to frost and killed completely by the first autumn freeze, completing its annual life cycle.
About This Grass
An aggressive, coarse annual grassy weed that grows in a sprawling, mat-forming habit. It has light green to yellowish-green foliage. Height can reach up to 1-2 feet if left unmowed, but it adapts well to low mowing by growing horizontally. Produces finger-like, digitated raceme seed heads in mid-to-late summer.
Blade Characteristics
Coarse blades (>4mm wide), flat, pointed tips, light green to yellow-green color, rolled in the bud (vernation). Features a membranous ligule, prominent veins, and hairs on both the blade surface and the sheath. Collar is broad with membranous auricles absent.
Root System
Fibrous and shallow root system with roots often forming adventitiously at lower nodes touching the soil. Rapid establishment from seed in spring, poor drought tolerance causing it to go dormant or die in extreme dry spells, but exceptionally persistent.
Growing Information
Origin Region
Europe and temperate Asia; now naturalized worldwide in temperate and tropical regions
Growth Habit
Stoloniferous and spreading prostrate to semi-erect, rooting at the lower nodes, forming coarse patches
Sunlight & Water Needs
Requires full sun (intolerant of dense shade), moderate to high water needs during germination and active growth, low drought resistance (goes dormant/turns brown quickly in drought), prefers moist, fertile, compacted soils with a wide pH range.
Mowing & Maintenance
Thrives under low to moderate mowing heights (1.0 to 2.5 inches). High maintenance as a weed due to its ability to spread rapidly via seeds and rooting stems. Controlled via pre-emergent herbicides in spring and post-emergence treatments.
Special Characteristics
High seed production, poor wear tolerance compared to dense turfgrasses, highly invasive in thin lawns, excellent at colonizing bare spots, compacted soil, and edges near sidewalks where heat radiates.
Ecological Information
Introduced weed species in North America. Provides minimal wildlife food value compared to native grasses. Often acts as an indicator species for thin turf, soil compaction, or improper watering and fertilization practices.