How to Grow: Japanese Stiltgrass


Wiki Commons: Katja Schulz

This time of year it’s important to be on the look out for weeds in the lawn and garden. One new Asian weed import that’s spreading around the state is Japanese stiltgrass.

Japanese stiltgrass stands out from common native grasses and lawn grass. It has lime green, 3-inch long tapered leaves. The stems can grow 3-feet tall if unmowed. Japanese stiltgrass grows in many locations, from wooded areas, along stream banks, in lawns, along driveways and in gardens. This annual grass can drop about 100 seeds from each plant and the seeds stay viable for up to 7 years. As if we didn’t have enough weeds to worry about!

The latest edition of Connecticut Gardener magazine highlights some control methods to eradicate this difficult grass. Watch for seedlings now and hand pull them. Don’t just grow them in the compost pile. It’s best to bag them up and leave the bags in a sunny, hot location for a few weeks to kill the plants. Continue pulling seedlings as you wander your yard and gardens this summer. It’s important to not allow the plants to set seeds. Mowing may be tempting, but Japanese stiltgrass will just grow laterally and still produce seeds. String trimming an area before seeds form then covering that spot with a deep mulch of wood chips is also an option. You’ll still have to watch for any emerging seedlings that manage to find their way through the wood chips.

With diligence, you can stay on top of this new invasive so it doesn’t crowd out native grasses and plants in your landscape.

Excerpted from Ct Garden Journal on Ct Public Radio