When The Comstock Park Downtown Development Authority built the Community Plaza pocket park on the corner of West River Drive and School Street, an infestation of Japanese knotweed was discovered. The Ottawa Conservation District treated the knotweed using grant money from the Michigan Invasive Species Program. It is impossible to get rid of the plant without proper treatment and improper efforts to get rid of the knotweed only stimulate the plant and cause it to spread faster.
“The more we learn about it (Japanese knotweed), the more we’re horrified,” said Jesse Schulte, District Administrator at the Kent Conservation District “When people take action…mow this plant…cut it back…smother it, it just makes more problems.”
The Kent Conservation District Invasive Species Strike Team has been treating an infestation of the knotweed along the White Pine Trail in Comstock Park this summer. A frost in the spring caused the knotweed to grow back with a vengeance, said Schulte. Stressors like frost or cutting actually invigorate the plant which spreads through its roots, grows up to four inches a day, and reaches as much as twelve feet high. Other infestations have been found in the area of Greenridge School and around Bud Street and Division Avenue. The plant likes natural areas like trails, roadsides, and streams. It prefers full sun, but tolerates multiple conditions.
The Kent Conservation District has funds from a Michigan Invasive Species Program grant to help property owners get rid of Japanese knotweed. If you think you have Japanese knotweed on your property there are steps to take before contacting the Invasive Species Strike Team. First, confirm that the plant is Japanese knotweed as it can be confused with other plants. The stems are bamboo-like. The leaves are two to seven inches long, about two-thirds as wide, spade-shaped, and have a narrowed leaf tip. Flowers are small, creamy white to greenish white, and grow in plume-like branched clusters.
To contact the Strike Team go to the Kent Conservation District web site www.kentconservation.org and click on the Japanese knotweed tab or the Invasive Species Strike Team tab. You will need the address and size of infestation, and the property owner’s legal name because the legal owner will have to approve the treatment. Planting or spreading Japanese knotweed is legally prohibited in Michigan.
Sources: Kent Conservation District, Japanese Knotweed Fact Sheet
Also visit: www.kentconservation.org
Japanese Knotweed Facts
- Native to Asia, Japanese knotweed was first introduced to England in 1850 for ornamental use, and to the United States in the late 1800’s.
- It cost 70 million pounds ($120 million US dollars) just to remove knotweed from the site of the London Olympic Games.
- A July 7, 2014 Newsweek Magazine article says the “ferocious” Japanese knotweed destroy property with its roots even spreading into building foundations. “Its tireless and unstoppable army of unseen roots…spreads out underground and forces its way up through every crack imaginable, in patios, concrete paths, and even in walls and floors. What’s more, getting rid of it is a task beyond the average gardener. It can take up to five years of regular chemical blitzing before the knotweed all-clear can be sounded.”
- In some countries property with Japanese knotweed cannot be sold or if the adjacent property has the knotweed.
- Not all cultures or countries think Japanese knotweed is bad. In Japan, where Japanese knotweed is indigenous, and China, Japanese knotweed is used in traditional medicine and for food.