Yellow Foxtail (Pigeon Grass)
Setaria pumila · Warm-season, Annual, C4
Grass Family
Poaceae, Subfamily Panicoideae, Tribe Paniceae
Grass Category
Invasive/Weed Grass, Pasture Grass
Variety / Cultivar
Common wild-type Setaria pumila
Hardiness Zones
Grown as a summer annual in USDA Zones 3-11. It dies back completely with the first hard frost but leaves behind a prolific seed bank.
About This Grass
An aggressive summer annual that forms spreading clumps. It reaches 1-3 feet tall if unmowed. The distinguishing feature is the 'bottle-brush' cylindrical seed head that turns yellow or golden-brown at maturity. The foliage is generally pale to medium green and has a somewhat coarse, sprawling messy appearance.
Blade Characteristics
Width: 4-10mm (coarse). Shape: Flat and lax. Tip: Pointed. Color: Pale green to yellowish-green. Vernation: Rolled. Distinctive feature: Long, flexible hairs (cilia) on the upper surface of the leaf blade near the base. Ligule: A fringe of short hairs.
Root System
Shallow, fibrous root system. Establishment is extremely rapid from seed in late spring and summer. It does not form a dense sod or produce rhizomes, but aggressive reseeding makes it persistent.
Growing Information
Origin Region
Native to Eurasia; naturalized throughout North America and worldwide temperate/tropical regions.
Growth Habit
Bunch-type (clump-forming) with a decumbent, spreading base that often roots at lower nodes.
Sunlight & Water Needs
Full sun preferred; poor shade tolerance. Low to moderate water needs. High drought tolerance once established. Thrives in disturbed soils with pH 5.5 to 7.5.
Mowing & Maintenance
In lawns, it requires frequent low mowing (under 2 inches) to prevent seed head formation, though it can adapt by producing seed heads very low to the ground. In pastures, it is managed as low-quality forage. High maintenance for removal as it requires pre-emergent herbicides.
Special Characteristics
Extremely high seed production (single plants produce thousands of seeds). Seed heads have soft yellowish bristles (setae). Known for invading thinning or over-fertilized lawns. Moderate salt tolerance but poor traffic tolerance compared to turf grasses.
Ecological Information
Introduced/Invasive in most turf settings. Seeds provide food for upland game birds and songbirds. Can be outcompeted by high-density, healthy cool-season or warm-season turf grass stands. Often found as a companion to large crabgrass in disturbed sites.