Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Wild type (Large Crabgrass / Hairy Crabgrass)
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 10 as a warm-season summer annual, dying completely with freezing winter temperatures.
About This Grass
Forms coarse, light green to yellowish-green patches that stand out against finer turfgrasses. Sprawls outward close to the ground before turning upward at the ends. Reaches heights of 6 to 24 inches if left unmowed. Produces finger-like (digitate) raceme seed heads in mid-to-late summer.
Blade Characteristics
Coarse blades (>4mm wide), flat, with pointed tips, light green to grey-green color, rolled in the bud (vernation), hairy surfaces (especially on large crabgrass), membranous ligule, no auricles, and a broad collar region.
Root System
Shallow, fibrous root system with stolons that root at the nodes. Fast establishment from seed in spring, forms a loose sod, prone to dying off with the first hard frost.
Growing Information
Origin Region
Europe and temperate Asia; now globally distributed as a common weed in lawns and agricultural fields
Growth Habit
Stoloniferous with a sprawling, mat-forming, and prostrate growth habit, rooting at the lower nodes
Sunlight & Water Needs
Requires full sun (poor shade tolerance), moderate to high watering, good drought dormancy capability, prefers warm temperatures and well-drained soils with a pH of 6.0 to 7.0.
Mowing & Maintenance
Mows well at standard lawn heights (1.5 to 3 inches). High maintenance if trying to eradicate due to prolific seed production. Controlled via pre-emergent herbicides in early spring and post-emergent spot treatments.
Special Characteristics
Low traffic tolerance compared to established turf, highly aggressive and invasive in thin lawns, excellent ability to outcompete desirable grasses in stressed or under-fertilized turf, poor winter color retention as it dies in autumn.
Ecological Information
Introduced weed species in North America. Provides minimal wildlife forage value compared to native grasses. Considered a persistent weed in managed turfgrass ecosystems, though seeds can be consumed by certain birds.