Large Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Wild type (common weed/pasture grass with no specific cultivated varieties)
Hardiness Zones
USDA Hardiness Zones 3 through 10 as a warm-season summer annual. Dies with the first hard frost.
About This Grass
An aggressive, low-growing summer annual weed grass. Forms coarse, sprawling clumps with light green to yellowish-green foliage. Height can reach 12 to 24 inches if unmowed, but usually forms dense, prostrate mats under frequent mowing. Seed heads feature finger-like racemes.
Blade Characteristics
Coarse blades (>4mm wide), flat, pointed tip, light to yellowish-green color, rolled in the bud (vernation). Blades and sheaths often possess hairy surfaces, especially near the collar region. Membranous ligule with no auricles.
Root System
Fibrous and shallow root system with stolons that root at the nodes when in contact with damp soil. Fast establishment from seed, enabling rapid takeover of thin lawns.
Growing Information
Origin Region
Europe and temperate Asia; now cosmopolitan and widely naturalized globally in warm-temperate and tropical regions.
Growth Habit
Stoloniferous and spreading; forms prostrate or semi-erect clumps with rooting at lower nodes.
Sunlight & Water Needs
Requires full sun and thrives in hot, dry, neglected areas with thin turf. High drought tolerance through summer dormancy if dry, but responds rapidly to summer rains. Prefers well-drained soils.
Mowing & Maintenance
Mows well at low heights (1.5 to 2.5 inches), but survives very low scalping by spreading horizontally. High maintenance required to eradicate; controlled primarily through pre-emergent herbicides, proper lawn thickening, and consistent mowing.
Special Characteristics
Exceptional heat and drought tolerance during summer. High tolerance to low mowing and compacted soils. Poor shade tolerance, unable to compete in dense, shaded lawns. Considered a noxious weed in turf settings.
Ecological Information
Introduced species in North America. Provides minimal forage value for livestock and wildlife, though seeds are eaten by some birds. Can become invasive in agricultural fields and disturbed lawns, outcompeting desirable turfgrasses.