Large Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Wild type, no specific cultivated varieties
Hardiness Zones
Thrives across USDA Hardiness Zones 3 through 10 as an annual summer weed, highly heat tolerant, killed by first hard autumn frost.
About This Grass
An annual grassy weed with a sprawling, prostrate to ascending growth habit. Stems can reach up to 2 feet in length when unmowed. Color is typically light green to yellow-green. Forms patchy, coarse clumps that compete aggressively with desirable turfgrasses in summer. Produces finger-like raceme seed heads in late summer.
Blade Characteristics
Coarse texture, blades are 3-10 mm wide, flat, pointed tip, light to yellow-green color, rolled in the bud (vernation). Membranous ligule with a hairy fringe, prominent collar region with membranous auricles absent.
Root System
Fibrous and shallow root system with roots often emerging from the lower nodes touching the soil (stoloniferous rooting). Fast establishment from seed in spring, low drought tolerance in extreme dry spells without intervention, but highly resilient during summer.
Growing Information
Origin Region
Native to Europe and temperate Asia; now cosmopolitan and widely naturalized throughout North America and globally in temperate and tropical regions.
Growth Habit
Stoloniferous and spreading, rooting at the lower nodes, forming loose mats.
Sunlight & Water Needs
Requires full sun, does not tolerate heavy shade. Moderate to high water needs for germination and rapid growth. Moderate drought tolerance by going dormant or surviving in dry soils until rain occurs. Prefers warm soils and fertile, well-drained conditions.
Mowing & Maintenance
Resilient to mowing due to its prostrate growth habit below standard mower blades. Mowing height needs to be maintained higher to shade out germinating seeds. High maintenance weed control required via pre-emergent and post-emergent herbicides.
Special Characteristics
Poor wear tolerance for heavy traffic, highly aggressive weed that crowds out thin lawns, excellent adaptation to compacted soils, high seed production capacity, difficult to eradicate once established without chemical controls.
Ecological Information
Introduced species often considered a troublesome agricultural and turf weed. Provides minimal wildlife food value compared to native grasses. Acts as an indicator of thin turf, soil compaction, and overwatering or underwatering practices.