Yellow Foxtail
Setaria pumila · Warm-season, Annual, C4
Grass Family
Poaceae, subfamily Panicoideae, tribe Paniceae
Grass Category
Invasive/Weed Grass, Forage Grass (limited use)
Variety / Cultivar
Not applicable (wild species)
Hardiness Zones
USDA Zones 3-11; survives as seeds through winter; thrives in temperatures above 80°F.
About This Grass
An upright to semi-prostrate annual grass reaching 1-3 feet in height. Known for its cylindrical, bristly, spike-like panicles that resemble a fox's tail, turning a tawny yellow-gold at maturity.
Blade Characteristics
Blades are 4-10mm wide (coarse), flat, and 2-12 inches long. A distinctive feature is the presence of long, wispy hairs on the upper surface near the base (leaf sheath). Ligule is a fringe of short hairs; auricles are absent; vernation is rolled.
Root System
Fibrous, shallow root system. Lacks specialized structures for spread, focusing energy on high-speed summer germination and rapid seed heading.
Growing Information
Origin Region
Native to Europe and Asia; naturalized throughout North America in disturbed sites and pastures.
Growth Habit
Bunch-type (clump-forming) or semi-prostrate; lacks rhizomes and stolons; spreads via prolific seed production.
Sunlight & Water Needs
Full Sun; highly adaptable to various moisture levels but thrives in moist, fertile soils; drought-tolerant once established.
Mowing & Maintenance
Low maintenance (as a weed); in lawns, it should be mown low to prevent seed head formation, though it can adapt by flowering below mower height. Not typically fertilized intentionally.
Special Characteristics
High seed production (up to 500 seeds per head); seeds remain viable in soil for years; can be toxic to horses if hay contains high concentrations of seed heads due to physical irritation (setae).
Ecological Information
Introduced/Invasive in turf and crops; seeds provide food for songbirds and upland game birds; often a pioneer species in disturbed soils.