Dallisgrass
Paspalum dilatatum · Warm-season, Perennial, C4 grass
AI-generated identification · may be incorrect
Grass Category
Pasture/Forage Grass, Invasive/Weed Grass in lawns
Hardiness Zones
Thrives in USDA Hardiness Zones 7-10. Good heat tolerance, moderate cold tolerance, goes dormant and turns brown with the first hard frost.
Grass Family
Poaceae, subfamily Panicoideae
Variety / Cultivar
Common wild type
About This Grass
Forms large, coarse, low-growing clumps with wide basal leaves. Unmowed flowering stalks can reach 2 to 4 feet tall. Color is a light to medium green. Distinctive seed heads feature 2 to 7 alternate, dark, hairy, finger-like racemes along the stem, often infected by a dark sticky ergot fungus.
Blade Characteristics
Coarse blades (>4mm wide), flat, pointed to acute tip, light to yellowish-green color, rolled in the bud (vernation). Prominent membranous ligule, collar is continuous and broad, auricles absent.
Root System
Deep, robust fibrous root system with short rhizomes. Establishes quickly in moist areas, highly resilient once established, making it very difficult to pull out manually.
Growing Information
Origin Region
Native to South America (Brazil and Argentina); widely naturalized in warm-temperate and subtropical regions globally, including the southeastern and southern United States.
Growth Habit
Bunch-type (clump-forming) with short, stout rhizomes forming a coarse, clumping turf.
Sunlight & Water Needs
Requires full sun. Prefers moist to wet, poorly drained, heavy clay soils but adapts well to various soil types. Moderate to high water requirement; exhibits fair drought dormancy.
Mowing & Maintenance
Mow at 1.5 to 2.5 inches. Due to its rapid vertical growth of seed stems, it often outgrows surrounding lawn grass between mows, requiring frequent mowing. High maintenance as a weed in fine turf, low maintenance in pastures.
Special Characteristics
Poor wear tolerance in fine turf settings due to clumping nature, but high persistence. Susceptible to ergot fungus on seed heads which can be toxic to livestock. Highly invasive in lawns, difficult to control selectively.
Ecological Information
Introduced species in North America. Valued as forage for livestock in pastures, though ergot toxicity can be an issue. Provides soil stabilization in damp areas but acts as an aggressive weed in managed turfgrass ecosystems.