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, tribe Andropogoneae
Variety / Cultivar
Wild type (no cultivated varieties)
About This Grass
An annual grass with a delicate, sprawling appearance, growing up to 2-3 feet long or tall when supported. Features pale green, lance-shaped leaves and slender, delicate terminal and axillary spike-like racemes bearing tiny seeds.
Blade Characteristics
Blades are short (1 to 3 inches long), relatively wide (5 to 15 mm), lance-shaped, flat, with an off-center silvery stripe of reflective hairs along the midrib on the upper surface. Tips are pointed. Vernation is rolled.
Root System
Shallow, fibrous root system with weak anchorage, making it easy to pull by hand. Often roots at the lower stem nodes where they touch the ground.
Growing Information
Origin Region
Native to Asia (China, Japan, Korea, India, Malaysia); naturalized extensively in the Eastern United States.
Growth Habit
Stoloniferous and branching; roots at the lower nodes to form dense, sprawling mats.
Sunlight & Water Needs
Highly shade tolerant, but also grows well in full sun. Prefers moist, shaded soils, floodplains, and disturbed woodlands. Low drought tolerance.
Mowing & Maintenance
Considered an invasive weed; controlled by frequent mowing, pulling, or herbicide application. Low maintenance as a weed, highly undesirable in lawns.
Special Characteristics
Exceptional shade and moisture tolerance; spreads rapidly via seed and rooting stems; crowds out native understory vegetation in forests; low wear tolerance.
Ecological Information
Highly invasive in North American forests and wetlands, threatening native biodiversity. Offers little to no positive wildlife value while severely altering natural habitats.