Japanese Stilt grass invasion

Asked March 16, 2016, 1:25 PM EDT

Last year we were inundated with Japanese Stilt Grass. We didn't realize what it was and mowed it - probably when it was flowering so that the seeds were cast everywhere. I've heard a few different thoughts on what I should do to get rid of it this year. One was that I should use a pre-emergent early spring then again in the summer. When I went to buy the pre-emergent after reading the uses and talking to other folks, they said it wouldn't work. The next advice is to use Round-Up or a similar product to kill everything and then replant our yard. Whichever will work is fine but I'd like to be sure whichever way I go that it takes care of it. Your advice is appreciated! Gordon Dugan

Monroe County Pennsylvania

1 Response

Japanese stilt grass is becoming a scourge of the Poconos. It insinuates itself into every nook and cranny and is difficult to scout out and kill. The best treatment is to us a preemergent herbicide like Preen. The preemergent works by hardening the seed coat so the seed can't germinate. The battle will require persistence since new seeds will blow in from nearby infected areas. I personally have pulled it, used a weed torch on it, and tried an herbicide called Grass B Gon by Ortho. This product kills grass but not broad leaf plants. I suggest that you try to make removing this invasive a neighborhood effort to get rid of new sources of weed seeds.