Crabgrass (specifically Large Crabgrass)
Digitaria sanguinalis · Warm-season, Summer Annual, C4 photosynthetic pathway
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Common wild type (not a cultivated variety for turf)
Hardiness Zones
USDA Zones 2-11; heat tolerant but killed by the first hard frost; seeds remain dormant in soil for many years.
About This Grass
A coarse-textured, low-growing grassy weed that forms a prostrate, star-shaped rosette (crab-like appearance). It is pale green in color, turning reddish-purple after the first frost before dying with winter temperatures. Seed heads are multi-fingered racemes (digitate).
Blade Characteristics
Coarse blades, 4-10mm wide; flat shape with pointed tips; medium to light green color; rolled vernation in the bud; leaf surface and sheaths are typically hairy (pubescent). The ligule is membranous with a jagged edge; auricles are absent.
Root System
Shallow fibrous root system; lacks rhizomes and stolons but stems root at nodes when touching moist soil; extremely fast establishment; low thatch tendency but creates dense mats that smother desired turf.
Growing Information
Origin Region
Native to Europe and Asia; highly invasive and naturalized throughout North America and temperate/tropical regions worldwide
Growth Habit
Bunch-type and decumbent; stems grow prostrate along the ground before turning upward, often rooting at the lower swollen nodes
Sunlight & Water Needs
Full sun (low shade tolerance); requires minimal water once established; high drought tolerance; thrives in compacted, low-quality soils with pH ranging from 5.5 to 7.5.
Mowing & Maintenance
Extremely low maintenance (as it is a weed); survives very low mowing heights (~0.5 inches) by growing prostrate. Controlled via pre-emergent herbicides in early spring or post-emergent selective herbicides.
Special Characteristics
Excellent wear tolerance; highly prolific seed producer (up to 150,000 seeds per plant); capable of thriving in cracks in pavement; survives in nutrient-poor soil where lawn grasses fail.
Ecological Information
Introduced/invasive status; seeds provide food for some songbirds and small rodents; provides minimal soil stabilization compared to perennial grasses; primarily acts as a pioneer species in disturbed soils.