Japanese Knotweed target of invasive plant treatment along Red Run

Jun 02, 2024

Lake St. Clair Cooperative Invasive Species Management Area (CISMA) will be managing invasive plant treatment along the Red Run Drain beginning on Wednesday, Aug. 9.

The target species for this round of spraying is Japanese Knotweed, a highly invasive and extremely resilient plant that is also known as Michigan Bamboo because of its resemblance to Bamboo.

“Trying to remove Japanese Knotweed can be like poking the bear because if you start messing with it, it just comes back worse than ever,” said CISMA Director Amanda Ruffini. “The best thing that you can do is not mow it, because if you do, it will spread and multiply.”

Target plants along the Red Run Drain will be foliar sprayed with ClearCast (Imazamox), AquaNeat (Glyphosate), and a Cygnet Plus surfactant. A blue dye will be added to the spray to mark treated plants. Bright yellow signs will also be placed just outside treatment area boundaries to alert the public of any usage restrictions.

Mature Japanese Knotweed has large outer leaves which will absorb the herbicide, draw it into its long roots, and ultimately kill the plant.

“A lot of homeowners like to spray in the spring, which does not work,” said Ruffini. “You have to wait until the growing season is done so that the herbicide gets to the roots through the leaves.

“Japanese Knotweed can grow through pavement and can crumble the foundation of your house and destroy infrastructure.”

Ruffini notes that it is now illegal to buy, trade or sell Japanese Knotweed in the United States.

“The more we are proactive, the more we can keep invasive species of plants from spreading,” said Rufini.

This round of spraying will be done by a contractor hired by CISMA and is partially funded through a Great Lakes Restoration Initiative grant through the United States Forestry Service.

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