Japanese Stilt Grass
Origin: Japan, Korea, China, Malaysia and India
Japanese stilt grass was first introduced into the United
States in Tennessee around 1919 and likely escaped as a
result of its use as a packing material for porcelain.
Distribution and Ecological Threat
Japanese stilt grass is currently established in 16
eastern states, from New York to Florida. It occurs on
stream banks, river bluffs, floodplains, emergent and
forested wetlands, moist woodlands, early successional
fields, uplands, thickets, roadside ditches, gas and
power-line corridors, lawns and gardens. Japanese stilt
grass threatens native understory vegetation in full sun
to deep shade. Stilt grass readily invades disturbed
shaded areas, like floodplains that are prone to natural
scouring, and areas subject to mowing, tilling and other
soil-disturbing activities including white-tailed deer
traffic. It spreads opportunistically following
disturbance to form dense patches, displacing native
wetland and forest vegetation as the patch expands.
Japanese stilt grass appears to be associated with moist,
acidic to neutral soils that are high in nitrogen.
James H. Miller
Description and Biology
Plant: an annual in the grass family (Poaceae)
resembling a small, delicate bamboo; mature plants are
2 to 3 feet in height.
Leaves: pale green, lance-shaped, about 3 inches in
length, with a distinctive silvery stripe of reflective
hairs down the middle of the upper leaf surface.
Flowers, fruits and seeds: delicate spikes of flowers
emerge from slender tips in late summer and early fall.
Fruits are produced shortly after flowering and then
the entire plant dies.
Spreads: vegetatively by rooting at joints along the
stem (a new plant can emerge from each node) and by
seed. A single plant can produce 100 to 1,000 seeds
that remain viable in the soil for at least three
years, ensuring its persistence. Stilt grass seed
germinates readily following soil disturbance. Although
dispersal is not fully understood, seeds are probably
transported by movement of water e.g., (surface runoff, streams, and floodwaters), soil, plants and on the feet of animals including people.
Look-alikes: Virginia cutgrass (Leersia
virginica), Pennsylvania knotweed (Polygonum
persicaria), other delicate grasses.
Prevention and Control
Because it is similar in appearance to several native
grasses, it is important to know how to recognize and
differentiate stilt grass from look-alikes. The shiny silvery midrib of stilt grass is a handy diagnostic character. Early attention to new infestations
should be a priority. Because it is shallow-rooted, stilt
grass may be pulled by hand at any time. Flowering plants
can be cut back using a mower or weed whip prior to seed
production. For extensive infestations, contact and
systemic herbicides may be more practical and effective.
Following disturbance to an area susceptible to
stiltgrass, stabilize with native vegetation suitable to
site conditions. Refer to
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