Japanese Stiltgrass – Now you know
You are probably not noticing a major vegetative scourge sweeping through Eureka Springs like an ocean of Kudzu. It’s a little too subtle to notice unless you know what you’re looking at. It creates a lovely, low, bright green monoculture. The problem is it is completely obliterating native vegetation and habitats, and has moved so quickly and is so stealth, you don’t even notice it.
Drive down the lower, one-way half of Wall Street, especially on the bottom half of the street and look out the passenger window. Lovely green grass, right? No, it’s our worst weedy nightmare – Japanese stilt grass (Microstegia vimineum). It goes by names such as packing grass, Nepalese browntop, bamboo flexible seagrass, and other names, most of which point to its Asian origins.
Japanese stiltgrass is an annual that germinates early in the spring, but seeds later in the season from mid-September through October. The leaf blades are shorter than most grasses, borne on a relatively short, usually less than 8-inch high, brown stem. When the leaves die off after flowering (and the worst part – seeding) in the fall, a naked brown stalk is left. There are plenty of websites from regions all over the country that include detailed information on its identification and eradication (usually by using a slew of herbicides). The plant dies with a hard frost but leaves a healthy seed bank behind.
It is usually found in moist, shady, disturbed sites, like ditches, garden edges, and somewhat open shaded woods, or which we have an abundance in Eureka Springs. One of its more dramatic infestations is as you’re coming up Dairy Hollow Road to Spring Street, and the entire hollow on the right side of the street in Harmon Park is now a sea of Japanese stiltgrass.
One of the best websites to see the plant at its various stage of growth is produced by North Carolina State University Extension services
I have never paid a whole lot of attention to the identity of grasses, but I learned about this plant on an Arkansas Master Naturalist hike a couple of years ago. Before that, to me, it was just another short green grass underfoot. What do we do about it? I don’t really know the answer to that, but whatever we can do will start with awareness of the existence of this plant.