by Alex Nuti-de Biasi, the Journal-Opinion
GROTON—In stifling, almost oppressive heat and humidity, a small troop of aged, sweaty volunteers waged war against an invasive pest proliferating across the landscape.
On the eighth day of the campaign, total combat had reached its zenith. Thousands of victims had been scythed down in the primes of their lives. The fields of battle teemed with heaps of rotting cadavers.
Alan Eastman was gleeful. Japanese knotweed is a formidable opponent. The invasive weed aggressively expands, forming massive blocks of tall canes that completely crowd out native species reducing biodiversity.
It shoots up out of the earth every spring and can grow up to 15 feet in height by July.
“That’s the stunning piece,” Eastman said. “Have you ever seen anything like that?”
In addition to all the space it occupies above ground, another problem is what lies beneath. “It will target weak spots in buildings, crack masonry, split pipes, and ravage foundations,” states a handout prepared by Eastman and others and distributed to community members. “It will infiltrate even the smallest and thinnest of cracks and wind its way through drains and septic systems, blocking and eventually breaking pipes. The damage can be extremely costly to a property owner, and its presence will lower property values, and could prevent a potential sale.”
So in 2023, Eastman stood up at town meeting and asked what the municipality wasdoing about knotweed. Not much, it turned out.
Groton is hardly alone. Across Vermont and beyond, Japanese knotweed is thriving. And yet, there appears to be little resolve and no strategy to take on the invasive plant.
Why? It’s stubborn and difficult to eliminate, Eastman said.
“Up to two-thirds of the mature plant’s biomass is stored underground in its system of rhizomes. Cutting or mowing knotweed only removes the above ground portion and only serves to stimulate the rhizome to send up additional shoots. The rhizomes can go down 8 feet, so digging is unlikely to remove them, and every small piece of rhizome can produce another plant.”
Undaunted, Eastman formed an invasive species working group that collaborates with the town of Groton. He enlisted the help of Dale Thorensen and Cindy Spoor for the working group.
Last year, with the support of the town, they conducted a test. They identified a few blocks of knotweed at the town’s former stump dump off of Little Italy Road and next to the Wells River. It’s the same location of the prospective Groton Gateway Park.
Eastman said the knotweed eradication project complements development plans for the Gateway Park. With weed-whackers, they cut down the canes.
A few weeks later, a certified pesticide applicator injected glyphosate into the canes.
Eastman acknowledged the concerns that some have about glyphosate, the ingredient that was once used in the widely available Roundup pesticide. He dismissed those concerns however, noting that there are many other household products that are more toxic than glyphosate.
State regulators have also found glyphosate is safe to use. According to the Vermont Agency of Agriculture, Food & Markets, the herbicide is used widely and breaks down quickly in most environments.
On July 10, Eastman and Thorensen took a reporter to the site and showed cell phone photos of the parcel before they cut down the canes. Where just last summer there was once vast blocks of knotweed, native shrubs and bushes have returned attracting insects and pollinators.
A few modest shoots of knotweed are visible. Eastman said they will need occasional spot treatments until completely removed. This year, the working group applied for a grant from the state. They received $6,000 to help fund an expansion of the glyphosate treatments throughout the village.
In the lead-up, they worked with private property owners to obtain permission to cut down canes and then apply the herbicide.
One of those property owners is Chuck Gallagher. He owns a couple of village parcels, including the building housing the former Brown’s Market Bistro and Sarky’s Smokehouse restaurants, in the village. When he bought the properties in 2008, knotweed was present but in a “much more modest form.”
He kept it under control with tarps, but after eight years away he returned to find the plant had practically taken over.
“It’s a very persistent plant,” Gallagher said. “It’s almost alien-like. There are so many invasives, but this is one of the most disturbing ones.”
His support for the experimental program did not stop at providing permission for the herbicide treatments. He joined Eastman and Thorensen last week to cut down the canes. “They make a pretty compelling case,” he said, sipping on a cold beverage during a brief respite from the work.
Eastman, Gallagher, and Thorensen spent about 3.5 hours per day for eight days with weed whackers cutting down the canes. On July 10, they started at 7 a.m. to avoid the worst of the heat. Ahead of a forecasted heavy rainfall, Eastman said they hoisted the cut canes up over the bank to keep them from being washed downstream. He estimated they cut down 3 acres of knotweed across 17 different riverside parcels roughly between the Groton Baptist Church and Mill Street.
The ambitious, experimental program to eradicate Japanese knotweed from Groton village is driven by volunteers. If successful, Eastman hope the pilots will inspire other communities to take action. “We will teach them,” said Eastman. “You can do something about it.”