State escalates efforts in noxious weed struggle

Published 10:42 am Thursday, July 25, 2013

DULUTH (AP) — Noxious weeds are proving an expensive and cumbersome adversary for Minnesota agricultural officials, who are ramping up eradication efforts of invasive plants that pose environmental or health worries.

In Duluth, Japanese knotweed has become a nuisance and prompted worry that it will crowd out food sources for waterfowl. In southern Minnesota, a woody vine called oriental bittersweet is spreading fast along the Mississippi River.

“There’s some pretty serious infestations in Winona that are just amazing,” said Anthony Cortilet, the Department of Agriculture’s noxious weed program coordinator. “You can’t even see spruce trees, because this stuff just climbs up over them, and covers them, and eventually it breaks trees. It’s pretty serious.”

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A recent $350,000 state grant from the state’s Environment and Natural Resources Trust Fund will help target weeds on an “eradicate list.” They include oriental bittersweet, Dalmation toadflax, Cutleaf teasel, Japanese hops and Grecian foxglove.

It’s a shift in focus because officials say that until now most funding has been geared toward enforcement and education.

“It’s really the first time that we’ve been able to get some money for direct boots-on-the-ground type of management, and that’s really needed here in Minnesota,” Cortilet said.

Along the Keene Creek in West Duluth, parks and recreation official Judy Gibbs surveyed a dense thicket of the Japanese knotweed that towers more than 10 feet high.

“This stuff grows so fast,” said Gibbs, who oversees trees and trails for the city. “That area is an important bird area for waterfowl, all kinds of migrants, so if this got along the St. Louis River, it would be devastating.”

Resident Lowell Cobb first saw the flowering stalks in his yard as beautiful and encouraged them. Now, he views it “like a cancer. It’s going to take over unless I do something about it.”

He has taken part in a workshop to get tips on how to remove the plant from their property. The first step is to cut the stalks and then apply herbicide. Experts caution it can take three to five years of weekly applications to finally kill the plant.

It’s a battle being fought on multiple fronts. The state Department of Natural Resources is waging a public education campaign called “Play Clean Go.”

DNR terrestrial invasive species coordinator Laura Van Riper said the agency wants to educate the public about invasive species that spread across the land in the same fashion it warns boaters about zebra mussels and other pests in lakes and rivers. Van Riper said preventing an invasive plant from taking root in Minnesota is much easier than trying to eradicate it once it’s here.