January 7, 2009

Invasive Japanese stilt grass

Japanese Stilt Grass — or Microstegium vimineum is one of the worst invasive plants in our area. It is a summer annual grass, native to Japan, Korea, China, Malaysia and India. It was accidentally introduced into the United States around 1919 in the state of Tennessee. It apparently was used as packing material for porcelain from China and this may have been how it was introduced into the U.S. It was first discovered in the U.S. in Tennessee in 1919. Microstegium has spread through much of the East, and is found throughout Virginia.

Our local Native Plant Society members aggressively pull it up on their nature walks. Local chapter president, Helen Hamilton, says stiltgrass “is a nasty invasive, but harmless-looking grass. It furnishes no nutritive value to wildlife and rapidly outcompetes all natives” including wildflowers and tree seedlings. It also creates an excellent habitat for ticks, chiggers, mice, and snakes.

If you have stilt grass on your property, the most ecologically-sound control is to pull it up NOW before seed production is complete by late September. For large patches, mow or weed-whack it. Herbicides such as Roundup can help control it, but be sure not to use products like this near watersheds.

Many homeowners cannot identify this invader that’s often called the “crabgrass of shade.” See www.nps.gov/plants/alien/fact/mivi1.htm to help you recognize it. If it’s in a natural area, it may be more than two feet tall by October.

Kudos to Historic Rivers Master Naturalists for risking poison ivy rashes and pulling out these and other invasive plants. Contact them to volunteer.