Crabgrass (Large Crabgrass)
Digitaria sanguinalis · Warm-season, Annual, C4
AI-generated identification · may be incorrect
Grass Category
Invasive/Weed Grass
Hardiness Zones
USDA Hardiness Zones 3 through 10 as a warm-season annual, completing its lifecycle in one growing season and dying with the first hard frost.
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Variety / Cultivar
Wild type / Common Large Crabgrass
About This Grass
An annual grassy weed with a spreading, low-profile growth habit. Stems branch heavily at the base, often lying flat or ascending at the tips. Height reaches 6 to 24 inches if unmowed. Color is light green to bluish-green, sometimes purplish in autumn. Texture is coarse. Seed heads consist of 3 to 13 finger-like racemes arranged in a whorl or near-whorl at the top of the stem.
Blade Characteristics
Blades are medium-width (4-10 mm), flat, sparsely hairy on both surfaces, with a pointed tip. Vernation is rolled in the bud. Ligule is a tall, jagged, membranous structure. Auricles are absent. Collar is broad and continuous with prominent hairs.
Root System
Shallow, fibrous root system with weak persistence due to annual life cycle. Roots easily from lower nodes touching the soil, allowing rapid spreading and establishment.
Growing Information
Origin Region
Native to Europe and temperate Asia; now naturalized worldwide in temperate and tropical regions.
Growth Habit
Stoloniferous and spreading prostrate, rooting at the lower nodes, forming loose mats.
Sunlight & Water Needs
Requires full sun and open areas with thin turf. Moderate to high water needs for rapid growth, but seeds remain dormant in dry soil until moisture is available. Low drought tolerance as a plant, though seeds are extremely drought-resistant.
Mowing & Maintenance
Grows vigorously and can produce viable seed heads even when mown very low (below 0.5 inches). High maintenance required to control via pre-emergent herbicides, hand-pulling, and maintaining a dense turf canopy.
Special Characteristics
Exceptional ability to invade thin lawns, tolerate compacted soils, and produce thousands of seeds per plant. Very poor shade tolerance, highly sensitive to frost, and generally considered an aggressive weed in managed turf.
Ecological Information
Introduced weed species in North America. Provides minimal wildlife value as a seed source for certain birds, but primarily functions as a colonizer of disturbed soils, bare spots, and agricultural fields.