Hand saws and herbicide: One Minnesotan's crusade against a killer vine

If you're driving around in Winona County and see a woman jump out of her car with a hand saw and bottle of herbicide, don't be alarmed.

It's probably Anne Morse, the county's sustainability coordinator — and leader of its effort to eradicate a vine called Oriental bittersweet before it takes down more of the region's trees.

The invasive vine is known for its red-orange berries and aggressive behavior.

"The vine will wrap itself around a standing tree and then just literally girdle it, like a python," said Morse, who developed an early appreciation for trees — her father was a botanist.

Several years ago, she toured some woodlands with some Minnesota Department of Agriculture staffers, who showed her what Oriental bittersweet was doing to trees.

How did it get here? Someone likely decided, 50 years ago, that the nonnative vine would look pretty in their yard, which, "we've come to realize, is just a really bad idea," Morse said.

Now, "it looks like a giant rat's nest, actually," she said. "You cannot even walk through the woods where this has had 51 years to grow. It's really horrifying."

But what could she do? Paying enough people to cut the vine and apply herbicide to eradicate it all at once wasn't possible within the county's budget. So instead, with help from a $22,000 state grant funded through lottery sales, Morse has been getting as many people as she can to care enough about the problem to do something about it.

"Once you show people what can happen when it's unaddressed, people say, 'Well, we can't let this continue,'" she said. "We just have to attack it."

So they did. Winona County hired interns to address some of the worst infestations. They taught landowners and other residents how to identify the vine and kill it. College students have helped out, and Morse has a core group of volunteers that follow her lead, carrying hand saws and herbicide on their regular hikes through the woods.

"There's not enough tax dollars, and it's actually our problem. I'm hopeful, and this year has made me believe that we can do our best and make real progress," she said.

The Minnesota Department of Agriculture has made an example out of Winona County's efforts by featuring it in a recent newsletter. Oriental bittersweet has been found elsewhere in the state, including in Red Wing, Duluth and parts of Washington County east of the Twin Cities, and it's among the invasive plants state officials are most concerned about.

"If we do nothing, it would devastate Minnesota's forests," said Christina Basch, a noxious weed eradication specialist for the ag department. "We need to do everything in our power right now when it's still controllable."

Help: Want to help eradicate Oriental bittersweet?

The first step is to confirm that what you're seeing is Oriental bittersweet and not American bittersweet, which is a non-invasive plant.

Winona County residents can get help identifying the vine by calling the county's environmental services department.

Once you've confirmed that you're looking at an invasive plant, the Minnesota Department of Agriculture recommends checking with a certified landscaper or local University of Minnesota Extension staff about options for applying herbicide. It doesn't do any good to only cut the vine, as it will grow back, sometimes more aggressively than before.

Correction: (Nov. 19, 2018): An earlier photo caption in this story incorrectly noted the places where Oriental bittersweet's berries grow. The caption has been updated.