08/29/2026
Today our post will be from 2021 and a timely post about invasive Japanese stiltgrass.
Japanese stiltgrass (Microstegium vimineum) is a VERY invasive grass that can invade lawns, landscape beds, and vegetable gardens. If left unchecked, Japanese stiltgrass will disrupt our native plant and animal communities, causing harm to our natural resources.
If you have stiltgrass, remove it NOW (if you haven't already) before it sets seed and you wind up with MORE stiltgrass next year!
Why is it bad?
-On a moist, shady, fertile site, stiltgrass can replace competing ground vegetation within 3-5 years, disrupting natural communities and causing harm to our natural resources.
- It's a shade tolerant plant that can survive and reproduce under a closed forest canopy--that means it can live in many different places!
-Japanese stiltgrass can produce large numbers of seeds – from 16,000 to 50,000 seeds per square meter.
What does it look like?
Japanese stiltgrass (Microstegium vimineum) is bright green with a distinctive silvery stripe of reflective hairs along the midrib of each narrow, lance-shaped blade. The leaves are one to three inches long and alternately arranged on a branched stalk resembling a smaller, more delicate version of bamboo. Flower spikes grow on top of each stem before the plant sets seed in late August to September. Growing one to three feet tall, Japanese stiltgrass has a sprawling, mat-like manner. At the end of the season, the plant dies back; in heavily infested areas it produces a thick layer of dried, tannish thatch.
Stiltgrass thrives in moderate-to-densely shaded areas subject to regular soil disturbances, such as flooding, mowing, tilling, and high foot traffic. Stiltgrass is commonly found along roadways and ditches, floodplains, moist woodlands, and power line corridors. Stiltgrass often thrives in soils that are moist, acidic to neutral, and fertile. Stiltgrass also threatens wooded areas where tree canopies are defoliated due to infestations of gypsy moths or other destructive events. In residential areas, stiltgrass can invade lawns, landscape beds, and vegetable gardens. Stiltgrass does not proliferate in full sunlight or in areas with standing water.
Where did it come from?
Native to Japan, China, central Asia and India. M. vimineum was originally documented in Tennessee in 1919 and is believed to have been accidentally introduced to the United States through its use as a packing material.
More info from:
NC State Extension: https://content.ces.ncsu.edu/japanese-stiltgrass-identification-and-management?fbclid=IwAR1GhnP7bCB1DN5fKap8udLo2xuWi7lb1yhuLpolqcERpj8kzotHHUr0bUc
Penn State Extension: https://extension.psu.edu/controlling-japanese-stiltgrass-in-your-garden
Maryland Extension: https://extension.umd.edu/hgic/topics/japanese-stiltgrass
Image shows four different examples of Japanese stiltgrass: one infesting a natural area and forming a groundcover, one in a pot, one close up of a patch growing in dirt, and one very closeup of the leaves.
