Japanese stilt grass: This invasive plant can be tricky to tame
A lush forest may look inviting but the growth of Japanese stilt grass can choke out other vegetation.
Seen here is a close-up of Japanese stilt grass. CONTRIBUTED PHOTOS
By now, we are all aware of how badly we are infested with invasive Japanese stilt grass.
It is evident along the road, in lawns and flower beds and, sadly, in the woods. I have it everywhere it could get a foothold.
This invasive is tricky. Because it has a shallow root system, we like to pull it out. However, the grass has laid down a seedbed, and when you pull out the parent, the child germinates. If we mow it, the grass responds by growing lower and flowering under the height of the mower.
In its native habitat, stilt grass is found near creeks and streams. The seeds are disbursed by water.
That makes our current weather patterns favorable for the spread and germination of stilt grass in open areas.
Once established, it has no trouble spreading into the damp soil in the woods. Wherever it grows, its roots interfere with existing vegetation and make it difficult for native trees and other plants to take up nutrition from the soil.
So what can we do about stilt grass on our landscape?
There are three methods that I find are helping me.
One is to flame it with a weed torch. This works great for garden beds and other places it shows up in nooks and crannies. With its shallow root system, the grass has a hard time recovering from having the top torched.
Bonus: the flame kills seeds lying under the plant.
Where I can, I mow it short and cover it with cardboard or newspaper topped with wood chips. That technique is called “denial of light.”
Stilt grass can’t creep around the cardboard because of its weak root system.
The other control I use is chemical.
For more information on herbicides, search PA DCNR stilt grass and read the PDF.
I have successfully used Roundup in areas where there was no problem spraying. I use the plastic bell that came with the herbicide to prevent drifting of the spray.
The important thing is to kill it before it flowers in August. It produces an enormous amount of seed and that seed stays viable for several years.
In time, perhaps stilt grass will develop natural enemies. That happens in many cases to invasive plants.
Right now it has none except us, so go after it and don’t let it creep into your woods.