Japanese stilt grass removal and prevention

Asked July 29, 2019, 10:52 AM EDT

What is the best way to remove Japanese stilt grass from a 2,000 sq foot pollinator garden? Must every small piece of this invader be removed from around our desired plants? Should we sacrifice desired plants in order to eradicate the stilt grass? Will heavy mulching prevent regrowth? Should we consider selective application of an herbicide? I am very resistant to this approach but the removal is a battle and volunteers are few. Thank you very much, Peggy

Baltimore Maryland

3 Responses

Because Japanese stiltgrass is an annual weed, preventing seed dispersal is a key to its management. Seeds of Japanese stiltgrass can persist in the soil ~5-7 years and will germinate when light/moisture conditions are favorable. Established plants will eventually die at the end of the season, but you will have to pull or cut/remove flowers before the plants disperse seeds. Since it is in an established garden, hand pulling is probably going to be your best option. The other option would be to use a nonselective, post-emergent herbicide on it--taking care to brush it on the weeds. You could use a sheet of cardboard to prevent spray damage to desired ornamental plants. Once the Japanese stiltgrass is removed, using a mulch layer will exclude light from the soil and help to keep seeds in the soil from germinating. Try to minimize soil disturbance (churning up seeds that are in the soil).

Here is our information about managing Japanese stiltgrass. https://extension.umd.edu/hgic/topics/japanese-stiltgrass

Rutgers University also has additional good information about options for managing it in landscape beds. https://njaes.rutgers.edu/fs1237/

Unfortunately, there are no easy solutions to this one.


Thank you Christa for the timely and helpful response. I wish that I had the energy of this plant invader!