Crabgrass
Digitaria sanguinalis · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Wild type
Hardiness Zones
USDA Hardiness Zones 3-10 as a warm-season annual completing its lifecycle in one summer season and dying with the first frost.
About This Grass
Crabgrass is a low-growing, coarse annual weed grass that forms spreading clumps and patches. It has a bright to light green color, medium-coarse texture, and grows rapidly in thin, stressed turf during summer. When unmowed, it can reach up to 1-2 feet in height with distinctive finger-like raceme seed heads.
Blade Characteristics
Blades are medium-coarse (4-10 mm wide), flat, pointed at the tips, and light to blue-green in color. Rolled in the bud (vernation). Features a membranous ligule and prominent hairs on the leaf blades and sheaths, with no auricles.
Root System
Shallow to moderately deep fibrous root system with stolons that root at the lower nodes. Fast establishment from seed, poor drought persistence in extreme heat unless watered, but highly opportunistic.
Growing Information
Origin Region
Europe and temperate Asia; now widespread globally in temperate and tropical regions
Growth Habit
Stoloniferous, spreading aggressively along the ground and rooting at the nodes to form loose, wide mats
Sunlight & Water Needs
Requires full sun and open areas; cannot tolerate heavy shade. Moderate to high water needs for rapid growth, but can survive dry spells by going dormant or relying on quick seed germination after rain.
Mowing & Maintenance
High maintenance weed; difficult to control once established. Mows low easily but survives by growing prostrate beneath mower blades. Controlled primarily through pre-emergent herbicides in early spring and post-emergents in summer.
Special Characteristics
Exceptional ability to invade thin lawns, excellent heat and light tolerance, poor wear tolerance compared to established turfgrasses, highly prolific seed producer allowing it to crowd out weakened lawns.
Ecological Information
Introduced weed species in North America. Provides minimal wildlife food value compared to native grasses. Acts as an indicator of thin turf, compacted soil, or improper mowing and watering practices.