Annual battle is afoot against noxious weeds in Kandiyohi County
WILLMAR — In late summer, the purple blooms of spotted knapweed spangle roadside ditches and wild areas around Kandiyohi County.
They look pretty but don't be fooled. Spotted knapweed is on Minnesota's hit list of noxious weeds because of its pesky propensity to invade pastures, meadows and fields and choke out existing vegetation.
Weed season is in full flower, bringing lots of phone calls this summer to Kandiyohi County Commissioners about sightings of spotted knapweed, wild parsnip, Canada thistle and more.
The noxious weed problem isn't necessarily worse this year than in other years, but current growing conditions are especially favoring the proliferation of spotted knapweed and wild parsnip and the public has noticed it, said Loren Engelby, public drainage manager for Kandiyohi County.
"Every year one or more species really thrives," he said. "Some grow really well in some years."
Although any unwanted plant can be considered a weed, noxious weeds are in a class by themselves. They might be less well-known than undesirable aquatic species such as the zebra mussel or starry stonewort, but they are just as damaging.
Earning a spot on the Minnesota Department of Agriculture's official list of noxious weeds is accomplished in one of two ways. A plant either must be known to be detrimental to human or animal health, public roads, crops or other property, or have the potential to be detrimental.
Some, such as Palmer amaranth, aren't yet widespread and are required by state statute to be eradicated when they're found and identified. Others are too well-established — Canada thistle, for example, which has been around since the late 1800s — to be eliminated but must be controlled to minimize further spread.
"They're all bad for specific reasons," Engelby said. "Many of them choke out or kill native species."
Noxious weeds are taken seriously all the way down to the local level. In Minnesota, townships and municipalities have their own weed inspectors. If a landowner fails to respond when notified that a noxious weed is growing on the property, local authorities can go in, eradicate the weed and bill the property owner for the cost.
This doesn't happen often in Kandiyohi County, Engelby said. Usually a conversation is all it takes, he said. "If you give somebody a phone call and say, 'I've got a complaint,' that sits a lot better."
Like other counties, Kandiyohi County also has a noxious weed appeals board to mediate disputes, but appeals are rare and most years the board doesn't meet at all.
Despite the resources and infrastructure dedicated to battling noxious weeds, it can be an uphill climb.
"We're trying to ramp up effectively, but you could spend thousands and thousands of dollars and not catch up," Engelby said.
Terrain is one of the challenges. Because of where they grow, many invasive plants are simply hard to get to — purple loosestrife, for example, which favors marshy areas.
The Kandiyohi County Highway Department and the Minnesota Department of Transportation work to keep noxious weeds in check along county and state highways, but effective options are limited.
"If it's really steep, you can't mow all of it," Engelby said.
Chemicals are sometimes deployed but they aren't always the best choice, especially when valuable crops are growing nearby, he said. "We're trying to make our best effort, but it does pose some challenges to control."
Roadside mowing also needs to be balanced with preserving pheasant habitat.
Some local government entities have gotten creative in the war against invasive plants. In several Minnesota cities, goats are being brought in to munch down thickets of invasive buckthorn. Natural insect enemies and plant diseases that specifically target certain noxious weeds also are frequently used.
But it's hard to not be outwitted by the tenacity of invasive plants and the ways they have evolved to persist and thrive.
"We can mow our ditches, but if it's a windborne seed ... we don't stand a chance," lamented Kandiyohi County Commissioner Roger Imdieke.
Engelby sees public awareness as one of the best weapons. With education, the public is better able to recognize noxious weeds — preferably early, before they have had a chance to flower and seed — and report them or take steps to eradicate them, he said.
"I encourage people, if you're going to own land, just do your best," he said. "It's a good time for all of us to be aware. Awareness is very, very important."