Japanese Stiltgrass
Microstegium vimineum · Warm-season, Annual, C4
AI-generated identification · may be incorrect
Grass Category
Invasive/Weed Grass
Hardiness Zones
USDA Hardiness Zones 5 to 9
Grass Family
Poaceae, subfamily Panicoideae
Variety / Cultivar
Not applicable (wild species)
About This Grass
An annual grass with a sprawling, delicate habit, growing from 1 to 3 feet tall. Leaves are pale green, lance-shaped, and asymmetrical with a distinct silvery line of reflective hairs along the midrib. Forms dense, uniform stands.
Blade Characteristics
Blades are flat, lanceolate, 5 to 10 cm long, and 4 to 15 mm wide with pointed tips. The midrib is distinctly off-center with a line of hairs. Vernation is rolled, and the ligule is a thin membrane.
Root System
Shallow, fibrous root system that easily pulls out of the ground; fast establishment from seed and rooting stolons
Growing Information
Origin Region
Native to Asia (India, China, Japan, Korea); naturalized extensively in the eastern United States
Growth Habit
Stoloniferous, spreading and rooting at the nodes to form dense mats
Sunlight & Water Needs
Highly shade-tolerant, also grows in full sun; prefers moist soils but adapts to various moisture conditions
Mowing & Maintenance
Not typically maintained as turf; controlled via pulling, herbicides, or mowing before seed set
Special Characteristics
Invasive weed with high shade tolerance, capable of outcompeting native understory vegetation, low wear tolerance as an annual
Ecological Information
Highly invasive in North American forests and wetlands; alters soil chemistry, reduces native plant diversity, and provides little value to native wildlife