Invasive grass

Asked August 16, 2018, 11:19 AM EDT

My front lawn has been overtaken by Japanese Stiltgrass, a.k.a. Chinese Packing Grass!!! It has also begun to make serious inroads in my backyard. While it has been pleasant to see a green lawn from a distance, I would much prefer the moss and clover that used to grow in my yard! Other than cutting the Stiltgrass before it flowers and drops seed, and waiting for Spring to apply crabgrass killer, what can be done to eliminate this invasive species?

Montgomery County Maryland weeds invasive japanese stiltgrass

1 Response

We are receiving a lot of questions about Japanese stiltgrass, which is having a banner year in the moist soil. Sadly, constantly mowing a lawn causes stiltgrass to grow at a lower height but still set seed. A more successful control strategy is to mow tall plants as they “flower” (starting about mid-August) and cut off the flowering culm (stalk of seeds) before the seed matures. You are too late for this as a lawn strategy, which requires letting the lawn go unmowed in late July-early August. And yes, applying a pre-emergent herbicide to the lawn next spring would also be part of the management process. For large areas, weed-whack the stiltgrass to ground level (bare earth), shortly before it produces mature seed but too late for it to regrow before the first frost. Because Japanese stiltgrass is an annual and has shallow roots, hand pulling is effective, too. We feel your pain.