Dallisgrass
Paspalum dilatatum · Warm-season, Perennial, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paspaleae
Grass Category
Invasive Weed in Turf / Pasture Grass
Variety / Cultivar
Common Dallisgrass (typically wild-type in turf settings)
Hardiness Zones
USDA Zones 7-11. Highly heat tolerant; goes dormant and turns brown after the first hard frost.
About This Grass
A coarse, tufted perennial grass that forms unsightly large clumps in lawns. It is a lighter yellowish-green compared to common turf. Seed heads are distinctive, featuring 3-5 drooping branches (racemes) with seeds arranged in rows.
Blade Characteristics
Coarse blades (5-12mm wide), flat, with a prominent midrib. Tips are pointed. Ligule is tall, membranous, and white. Absent auricles. Vernation is rolled in the bud. Leaves are mostly hairless except for a few hairs near the base.
Root System
Deep, fibrous root system with thick, fleshy rhizomes. Extremely difficult to pull by hand once established. Low thatch tendency but creates significant surface irregularities.
Growing Information
Origin Region
Native to Brazil and Argentina; widely naturalized in the Southern United States and California.
Growth Habit
Clump-forming bunch-type with short, thick rhizomes that allow it to spread into dense, circular mats.
Sunlight & Water Needs
Prefers full sun but very adaptable. High water requirement to thrive but possesses exceptional drought tolerance once established. Prefers moist, heavy clay or loam soils.
Mowing & Maintenance
Grows faster than most turf, requiring frequent mowing. Tolerates low mowing but thrives when left high. Extremely difficult to control chemically without killing surrounding turf. Maintenance: Low (as a weed).
Special Characteristics
Highly invasive in Bermuda and Zoysia lawns. Excellent wear tolerance and difficult to eradicate due to short rhizomes. Can be toxic to livestock if seeds are infected with ergot fungus.
Ecological Information
Introduced to the US as a forage grass. Provides seeds for songbirds, but is considered a major ecosystem disruptor in managed landscapes and a competitive weed in native grasslands.