How to Remove Japanese Knotweed
These recommendations are primarily for homeowners and communities that would like to start working in their neighborhood greenspace. For each species, we recommend herbicide-free control methods but have added an herbicide option for some species for those who are comfortable using them. These methods were selected while keeping in mind limiting soil disturbance, reducing herbicide use, and avoiding harm to other species that may be present whether they be other plants/animals. Manual removal is possible for all of them if you have the time. If the infestation is overwhelmingly severe/large, we suggest you look into professional control.
Removal Difficulty: Hard
This plant is one of the hardest plants for us to remove, even professionally.
Japanese knotweed leaves and flowers
Japanese knotweed stems
First, clear out the surface growth from previous growing seasons. Then, cover the area with a wire fence mesh with ½” x ½” openings. Fasten the fencing material down so that it will stay put throughout the growing season. The knotweed stems will grow through the steel mesh. As they grow, they will expand in diameter. Eventually, they will push against the mesh and girdle themselves. The surface growth will die back, but the rhizome will continue to push new stems through the wire mesh. The stems will continue to girdle themselves until the rhizomes carbohydrate reserves are depleted.
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