Large Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, Panicoideae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Not applicable (Common wild species)
Hardiness Zones
USDA Zones 2-11 (as an annual). It germinates when soil temperatures reach 55 degrees Fahrenheit and dies off during winter freezes.
About This Grass
A low-growing, coarse summer annual weed. It features light green to yellowish-green foliage and a prostrate growth habit. Seed heads are digital (finger-like) spikes from 2-6 inches long. It typically appears in late spring and survives until the first hard frost.
Blade Characteristics
Coarse blades (5-10mm wide), flat, with a prominent midvein. Tips are sharply pointed. Vernation is rolled in the bud. The ligule is membranous and tall; auricles are absent. Distinctive long, stiff hairs are often present at the base of the blade and on the sheath.
Root System
Shallow fibrous root system. It spreads primarily by tillering and by rooting at nodes of the stems where they touch the soil. Fast establishment from seed in disturbed or bare soil.
Growing Information
Origin Region
Native to Europe and Asia; highly invasive and naturalized throughout the United States and temperate/subtropical regions globally.
Growth Habit
Prostrate, spreading bunch-type that root at the nodes (decumbent); creates dense, radiating mats that crowd out desirable turf.
Sunlight & Water Needs
Full sun preferred; high drought tolerance once established. Thrives in compacted, poor, or frequently watered soils with a pH between 5.5 and 7.5.
Mowing & Maintenance
Highly adaptable to mowing; can set seed even at heights as low as 0.5 inches. In lawn settings, it is treated as a weed requiring pre-emergent herbicides in early spring and post-emergent selective herbicides.
Special Characteristics
Extremely high seed production (up to 150,000 seeds per plant); high traffic tolerance; thrives in heat and drought where turf grasses go dormant. Very poor shade tolerance.
Ecological Information
Introduced/Invasive status in North America. Provides some food for birds and small mammals via seeds, but generally considered a nuisance that outcompetes native flora and reduces biodiversity in managed landscapes.