Large Crabgrass
Digitaria sanguinalis · Warm-season, Summer Annual, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Invasive/Weed Grass, occasionally used for Pasture/Forage
Variety / Cultivar
Common wild type (cultivars like 'Red River' exist for forage, but this is a weed phenotype)
Hardiness Zones
Grows as a summer annual in USDA Zones 3-11. It dies with the first hard frost but leaves behind thousands of seeds that germinate when soil temperatures reach 55°F.
About This Grass
A coarse-textured, pale green summer annual that forms low-growing, star-shaped clumps. It can reach 2 feet if unmowed but typically sprawls horizontally. Seed heads are fingered spikes (racemes) arising from the top of the stem.
Blade Characteristics
Blades are 2-6 inches long, coarse (5-10mm wide), and tapering to a point. They are light green with a prominent midvein. The leaf sheaths and blades are notably hairy (pubescent). Vernation is rolled, ligule is tall and membranous, and auricles are absent.
Root System
Shallow, fibrous root system. Highly effective at establishment because it develops adventitious roots at the lower stem nodes (tilering) when they touch moist soil.
Growing Information
Origin Region
Native to Europe and Asia; widely naturalized throughout North America, especially the Southeast US including South Carolina.
Growth Habit
Prostrate and spreading; primarily bunch-type that roots at the nodes (stoloniferous-like behavior) to form dense mats.
Sunlight & Water Needs
Full sun preferred; highly opportunistic with water. Drought tolerant once established but thrives in moist, disturbed soils with a pH of 5.5 to 7.0.
Mowing & Maintenance
Extremely low maintenance as it is a weed; thrives under low mowing heights (1-2 inches) which encourages horizontal spread. Highly resistant to frequent mowing.
Special Characteristics
Major weed of lawns and gardens; high seed production (up to 150,000 seeds per plant); excellent heat tolerance; allelopathic tendencies that can suppress neighboring plants.
Ecological Information
Introduced/Invasive status in lawns. While seeds provide food for wild birds and the foliage is palatable for livestock (high protein forage), it is generally considered a nuisance in managed landscapes and turfgrass.
Notes
Summertime in sc