Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Wild type (smooth crabgrass Digitaria ischaemum or large crabgrass Digitaria sanguinalis)
Hardiness Zones
USDA Hardiness Zones 3-10 as a warm-season annual. Dies with the first hard frost.
About This Grass
Forms coarse, light green to bluish-green clumps that spread aggressively across bare spots and thin turf. Height reaches 6 to 24 inches if left unmowed, but usually remains low to the ground under regular mowing. Features characteristic finger-like seed heads at maturity.
Blade Characteristics
Coarse blades, 4-10 mm wide, flat, pointed tip, light green to grey-green color, rolled in the bud (vernation). Membranous ligule with no auricles.
Root System
Fibrous and shallow root system with stolons that root at the nodes. Establishes rapidly from seed in spring, forming a loose, non-durable sod.
Growing Information
Origin Region
Europe and temperate Asia; now globally distributed in temperate and tropical regions.
Growth Habit
Stoloniferous and prostrate, rooting at the lower nodes, spreading outward in a sprawling, mat-forming habit.
Sunlight & Water Needs
Full sun required; highly intolerant of dense shade. Moderate water needs, highly drought-tolerant by going dormant during extreme dry spells and recovering quickly after rain. Thrives in compacted, warm soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Mow at 1.5 to 2.5 inches. High maintenance as a weed, controlled primarily through pre-emergent herbicides applied in early spring and post-emergent spot treatments.
Special Characteristics
Exceptional heat tolerance, high adaptability to poor, compacted soils, excellent ability to invade thin lawns, moderate to low wear tolerance.
Ecological Information
Introduced species often considered an aggressive weed in managed turf. Provides limited food for ground-nesting birds and small mammals, but primarily acts as an opportunistic colonizer of disturbed soils.