Yellow Foxtail
Setaria pumila · Warm-season, Annual, C4
Grass Family
Poaceae, Panicoideae, Tribe Paniceae
Grass Category
Invasive/Weed Grass
Variety / Cultivar
Common Yellow Foxtail
Hardiness Zones
USDA Zones 3-10; germinates when soil temperatures reach 60-65°F and dies with the first hard frost in autumn.
About This Grass
An aggressive summer annual that emerges in late spring. It features a coarse, clump-forming structure with lime-green to medium-green foliage. If unmowed, it produces a distinctive, erect, cylindrical seed head that resembles a bottle brush with yellowish-orange bristles.
Blade Characteristics
Blades are coarse, 4-10mm wide, and flat. A key diagnostic feature is the presence of long, sparse hairs on the upper leaf surface near the base (throat). Tips are pointed. Vernation is rolled in the bud. Ligule is a fringe of hairs; auricles are absent.
Root System
Shallow, fibrous root system. It does not form rhizomes or stolons and relies entirely on prolific seed production for spread and survival in subsequent years.
Growing Information
Origin Region
Native to Europe and temperate Asia; naturalized throughout North America in disturbed soils
Growth Habit
Bunch-type (clump-forming) but can have a semi-prostrate growth habit in low-mown areas
Sunlight & Water Needs
Full sun preferred; high drought tolerance once established. Thrives in moist, fertile soils but can survive in compacted or poor-quality urban soils with a pH of 5.5 to 8.0.
Mowing & Maintenance
Maintenance involves prevention via pre-emergent herbicides. If mown, standard lawn heights of 2.5-3.5 inches are common, though it will adapt by producing seed heads at even lower heights. Requires no fertilization as it is a weed.
Special Characteristics
Highly competitive; its coarse texture and rapid summer growth allow it to crowd out desirable turf. It is salt tolerant and flourishes in high-heat environments where cool-season grasses may go dormant.
Ecological Information
Considered an invasive weed in managed turf and agriculture. While its seeds provide food for some avian wildlife and small mammals, it generally degrades the quality of pastures and can be an irritant to livestock due to the awns on seed heads.