Officials say Japanese knotweed moving into area

Leaves from the Japanese knotweed plant are pictured in this undated photo. Local officials say instances of Japanese knotweed being found in the Mecosta and Osceola county areas have increased recently. (Courtesy photo)

BIG RAPIDS — Japanese knotweed is described as a bamboo-like shrub with reddish stems that can grow up to 12 feet, and while some may find it beautiful, it can do serious damage to the environment.

While Japanese knotweed has been on the radar of environmental specialists in Michigan for roughly 10 years, officials in Mecosta and Osceola counties say the invasive species has slowly gained prominence in the local area during the summer months. They are urging locals to be on the lookout for Japanese knotweed in the hopes of halting its spread.

“It is one of those species that are a high priority, on our hit list, as I say,” said Rick Lucas, a forester with the Mecosta and Osceola-Lake Conservation Districts. “I’m starting to see it more and more, a lot of times in small clumps. Those are the easiest to address, if we know where they are.

“Early detection, probably more than any other aspect of dealing with these invasives, gives us far more opportunities to address something on a small-scale basis. Once it becomes widespread, we have to take a different approach. At some level, it’s more about management than trying to eliminate them.”

Joyce Coulson, a resident of Lakeview, said she recently became aware of Japanese knotweed due to an outbreak in nearby Edmore. She said that a crop of knotweed near her home is hard to miss.

“You can’t help but see it. It’s a huge bush on both sides of the road. The concern is that it keeps spreading,” Coulson said. “I’ve read that it’s impossible to kill.”

That’s not quite true, said Jerry Lindquist, a field crops and grazing expert at Michigan State University Extension, based in Reed City. Japanese knotweed is indeed known for its strength and resiliency — for example, in the United Kingdom, banks have denied mortgages for prospective homeowners on properties that contain the plant. But it can be managed.

“It takes multiple applications of herbicides,” Lindquist said. “You won’t be able to kill it with one treatment. I’ve had people that have been on a campaign and it usually takes two to three years of continued Roundup applications to get the plant and the root system under control.”

Lucas and Lindquist said Japanese knotweed often spreads in an area by similar means as other invasive species — through the air and the bodies of animals. However, the plant has an aesthetic appeal that sometimes leads unaware gardeners to plant it at home.

“A lot of times, invasives look nice,” Lucas said, “but once the seed source gets out there, it’s a real problem.”

Lindquist added: “People have to realize that while it may be an ornamental plant that they like to look at, it’s an invasive plant that will continue to spread from the mother plant. Its extensive root system can take over landscapes and grow out of control. It can take over road ditches and uncultivated land. It’s a concern for visibility and other factors.”

Lucas suggested anyone who suspects they have Japanese knotweed in their yards contact the conservation district, which can help with removal. The district can be reached by phone at (231) 796-0909.

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