How can I prevent ornamental grasses from self-sowing, and best way to kill seedlings?

Question

My landscape customer has about 75 ornamental grasses, and lives surrounded by woods. The grasses have been self-sowing (especially the Miscanthus) prolifically the past few years. Seedlings are popping up in the woods, in the neighbor’s yard, and particularly around the base of each grass, where babies are coming up in the hundreds! We have been cutting the grasses down in late November. What is the best way to kill the seedlings and mature plants that have come up in the woods? Is there a way to prevent this from happening? Chemical sterilization?

Answer 1

To prevent future self-sowing of established plants, clip and discard seed heads as soon as they appear so that they don't mature, blow away and re-seed themselves. Targeted spraying with the proper herbicide should kill the unwanted seedlings.

Here are a couple of articles about ornamental grasses in your region:

https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-5/invasive-zone-5-plants.htm

http://npic.orst.edu/pest/weeds.html

https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-6/zone-6-ornamental-grass.htm

Our best advice for eliminating the unwanted seedlings in the woods is to check with your local extension service to find out what methods are acceptable.