Japanese stilt-grass (Microstegium vimineum)

Invader Type: 


Mechanical Control: 

Hand pull: Stilt-grass is a weak rooted annual and small populations can be hand pulled any time during the growing season when the ground is soft. Be sure to pull up the entire root system. Pulling is easier and probably more effective in mid-to-late summer when the plants are much taller and more branched. Hand pulling of plants will need to repeated and continued for many seasons until the seed bank is exhausted.

Mowing: Larger infestations can be mowed or weed-whacked when plants are mature but seeds have not yet set. Because stilt- grass is an annual plant, cutting late in the season before the plants would die back naturally avoids the possibility of regrowth.

Chemical Control: 

Foliar spray: This method is used for dense populations and best left to a contractor. For extensive stilt-grass infestations, use of a systemic herbicide such as glyphosate is a practical and effective method if used with caution. Glyphosate is a non-specific herbicide that will kill or damage almost any herbaceous plant and possibly some woody plants it contacts. Grass-specific herbicides (graminicides) work very well on stiltgrass and if used correctly can reduce potential damage to woody or broadleaf plants


Pest Overview and Identification: 

Japanese stiltgrass is a delicate, sprawling, annual grass that is ½ to 3 ½ ft. (0.2-1.1 m) in height. The leaves are pale-green, alternate, lance-shaped, 1-3 in. (2.5-7.6 cm) long, asymmetrical with a shiny, off-center midrib. Stems usually droop. Flowering occurs in late-summer, when delicate flower stalks develop in the axils of the leaves or at the apex of the stems. Most commonly an invader of forested floodplains, stiltgrass is also found in ditches, forest edges, fields, and trails. It is very shade tolerant and can displace vegetation native to floodplains.  (Source: www.invasive.org)

Japanes stiltgrass is native to Asia and was accidentally introduced into North America sometime around 1920. It has previously been used as packing material for porcelain, possibly explaining its accidental introduction. (Source: www.invasive.org)
Reproductive Strategy / Lifecycle: 

Japanese stilt-grass reproduces exclusively by seed with individual plants producing 100 to 1,000 seeds that may stay viable in the soil for 3 - 5 years.


Ecological Threat: 
  • Where white-tailed deer are over-abundant, they may facilitate its invasion by feeding on native plant species and avoiding stilt-grass.
  • Infestations of Japanese stilt-grass change the habitat of the forest floor, making it less hospitable for ground nesting birds.