Targeting knotweed in Winsted

Robert Gambino supports his assistant on a 12-foot orchard ladder as the duo spray for knotweed.

Provided

Targeting knotweed in Winsted

WINSTED — North Canaan nature photographer and tree preservationist Tom Zetterstrom brought out a souvenir May 6 for the packed Winchester/Winsted Town Hall meeting room to see — a stalk of the plant itself, plucked that day from beside the “Welcome to Winsted” sign.

The presentation, which was hosted by the Winchester Conservation Commission and titled “Eradicating Japanese Knotweed Along Roadsides and Riparian Borders,” was loaded with similar warnings about allowing the tenacious plant to establish itself in Northwest Corner towns.

Zetterstrom said his intention for the presentation was to “bring the Housatonic model” to Winsted.

The “Housatonic model” refers to a knotweed survey, removal effort and shoreline restoration project that identified a large population of the plant just north of the West Cornwall covered bridge. Zetterstrom dubs that specific growth the “Wild and Scenic Housatonic Presentation Patch,” as it became a demonstration of the effectiveness of the herbicide glyphosate in dealing such robust growths of the plant.

HRC members and licensed herbicide applicators Robert Gambino and Christian Allyn treated the knotweed with the chemical in 2018 and 2019. After a few years, a few spot treatments and several more plantings, the area was restored to native plant habitat with minimal knotweed reemergence.

Zetterstrom said glyphosate works well for knotweed because it breaks down quickly and binds to soil, reducing the chance that it runs off into the river. When handled carefully, he said, it is easily controlled: “I guarantee not one droplet of glyphosate touched the river.”

While this population was a riparian (riverside) growth, Zetterstrom said that it had been introduced to the area by contaminated fill from the town of Canaan. This is a common occurrence, he said: “These stem fragments are being cultivated in a sense in every town gravel pit and land fill.”

He explained that roadside and riparian knotweed populations are deeply connected. Roads follow rivers, and as such, a seemingly inconsequential patch on the side of a highway could lead to a shoreline-choking infestation.

Japanese knotweed at its “full biological potential” becomes a “monoculture,” he explained — “it basically means it owns the land.”

This is a major issue for riparian ecosystems in which the aquatic life below the surface is deeply intertwined with what’s happening onshore. To illustrate the point, Zetterstrom referenced a study which found that rivers with knotweed-lined shores lost about 96% of their insect biomass, which could have dire consequences for the river’s ecology, such as for the trout that eat those insects.

“In terms of salmonids, that’s a bad story,” he said, noting that the renowned Housatonic trout fishery could suffer gravely.

The best way to avoid those situations is to locate the plant early on before it has the chance to deeply establish itself. While herbicides are his preferred method for treating monoculture growths, he said that other methods have also proven effective to varying degrees, especially with younger populations.

An intensive cutting regime — three times a summer for three years in a row — has yielded good results, however, careless mowing will only disperse the stalks elsewhere and spread the growth laterally.

A potential treatment involving the introduction of a Japanese insect that feeds on knotweed — and only knotweed — has also shown promise, though Zetterstrom said it lacks urgency: “It won’t solve the problem in my lifetime.”

Foraging goats have also been used, but Zetterstrom noted that 60% of the plant is underground and remains unaffected by their feeding. “There’s a certain romance to bringing in goats,” he conceded, though.

“Can you eat it?” shouted out an audience member during the Q+A portion of the evening, shifting the conversation to human diets. “Absolutely,” Zetterstrom replied — “I was even served it in Canaan,” though he compared it unfavorably to rhubarb.

“We’re not going to eat our way out of this,” he said.

For detailed information on knotweed management, a full recording of the presentation is available on the Town of Winchester’s YouTube page.

Latest News

Pirates go back-to-back as league champs

The Canaan Pirates pose as champions after defending the Northwest Connecticut District 6 Majors Little League title.

Photo by Riley Klein

THOMASTON The Canaan Pirates are champions once more.

In the Northwest Connecticut District 6 Majors Little League title game Friday, June 13, the Pirates defeated Thomaston JRC Transportation by a score of 6-2.

Keep ReadingShow less
Red Sox end season with comeback win

NORTH CANAAN — The Canaan Red Sox ended the season with a thrilling 14-13 win over the Tri-Town Phillies Thursday, June 12.

Canaan trailed for most of the game but kept it close. Ultimately, the Red Sox secured the victory with a final-inning comeback in front of the home crowd at Steve Blass Field.

Keep ReadingShow less
State Rep. Horn injured in running accident

State Rep. Maria Horn (D-64) was treated for her injuries at Sharon Hospital.

Photo by John Coston

The day after concluding what has been described as a grueling legislative session, State Rep. Maria Horn (D-64) had a running accident, leaving her with a broken pelvis and collarbone among other more minor bruises and abrasions. Despite the injuries, she is in good spirits and recuperating at home, eager to get back on her feet.

Horn said after spending weeks in the assembly hall, she was eager to get some outdoor exercise in, but perhaps pushed a little too hard too soon. She said she was excited to get a run in on the morning of Friday, June 6, but was still exhausted from her time in Hartford and in the final stretch of recovering from a meniscus repair surgery in December.

Keep ReadingShow less
Walk-off win sends Pirates to championship

Milo Ellison sends a fly ball to left field, bringing home Brody Ohler and Sam Hahn in a walk-off win for the Canaan Pirates June 11.

Photo by Riley Klein

NORTH CANAAN — The Canaan Pirates advanced to the league championship after a comeback victory over the Tri-Town Red Sox Wednesday, June 11.

Down 3-2 with two outs and two on in the bottom of the 6th inning, "Mighty" Milo Ellison stepped up to the plate and launched a fly ball deep to left field. The single brought home Brody Ohler and Sam Hahn for a walk-off Pirates win.

Keep ReadingShow less