Wellesley in knots over knotweed

Latin name: Fallopia Japonica. Commonly known as knotweed.

Crimes against Wellesley:

• Currently attempting a takeover of wide swathes of the 23-acre Brook Path, a publicly owned entity, along with other areas of town, both public and private
• Harassment of  government agencies—the Natural Resources Commission (NRC), the Wellesley Parks Division, the Department of Public Works
• Operating an impenetrable rhizome system without a license.

Action plan? Wellesley resident Herb Nolan and his daughter, front-line volunteers on a quest to eradicate knotweed from the Brook Path, have put together a plan that they’ve asked the NRC  to OK. The two have already, with approval, cleared knotweed by hand from an area by Cottage Street along an abutter’s property line. Now they have their sights on the bigger picture. Their goal is to free the 100+ year-old, 2.5-mile long walking route from knotweed.

Knot a good thing

 

Fuller Brook Park was established in 1899 and designed by John Charles Olmsted (nephew of Frederick Law Olmsted). The spot is considered a town treasure due to its historic nature and its level, peaceful walking path. In fact, a large portion of the park, which runs roughly parallel to Washington Street along Fuller Brook and Caroline Brook, is listed on the National Register of Historic Places.

Knotweed has been a problem along the Brook Path for years. The town stepped up its efforts to control the invasive species as part of the 2014-2017 Fuller Brook Park restoration project. At that time the DPW, along with outside contractor R. Bates & Sons, broke ground on a 3-year, $6M restoration project aimed at controlling erosion; making improvements to roadway drainage; stormwater remediation; reconstruction of pedestrian bridges; and more. Invasive species control was part of the restoration project.

Knot for nothing…

An NRC agenda item was put forth earlier this month by Nolan in order to bring the issue of knotweed on the Brook Path to the forefront. In introducing the topic at the meeting, NRC Director Brandon Schmitt shared with the NRC Board that one of the questions he gets most regularly from Brook Path walkers is, “What is that black plastic marring our beautiful park?”

He’s referring to the heavy, thick, rubberized material that can be seen up and down the path, lending an abandoned lot look to several parts of the park. “Most people feel the area would look better vegetated,” Schmitt said.  The material was laid down during the Fuller Brook Park project construction to halt the non-native knotweed’s aggressive spread. Schmitt showed the NRC Board pictures of the many sections along the Brook Path taken over by knotweed. Some shots showed the dreaded stalks coming right up through the black plastic. A tiny opening is all the encouragement knotweed needs to thrive. Just ask any stretch of asphalt that’s been pushed up to make for the voracious beast. Unchecked, the knotweed plant will reach a height of up to 12 feet, colonize any area it pleases, and dare you to stop it.

Over the past three years, Parterre Ecological has been working with the Wellesley Parks division to address immediate and ongoing needs throughout the park. The company comes in twice per week and helps with eliminating top-priority invasives  such as bittersweet, multiflora rose, and buckthorn.

As NRC Board Chair Raina McManus put it, “Bittersweet removal has been the priority because it can take down forests.” Knotweed removal, on the other hand, hasn’t been a focal species for Parterre and the DPW. They’ve controlled it by putting down the black plastic, called it good enough for now, and moved on to other things.

Although the black plastic doesn’t exactly fit in with the Olmstead aesthetic, the idea of removing the smother cloth, which was supposed to be in place for only a year or two, is unpopular with the DPW and the Parks Division. Basically they’ve heard from other towns that as soon as the black plastic gets pulled up, the knotweed comes back. “So we’ve left it,” Schmitt said, even though, “Effectively there are dead ecological areas covered in black plastic, unless we value the roots of the knotweed underneath to some degree.”

If  knotweed must be given some credit, it could be said that its late-summer flowers do help bees. In addition, their rhizome system could be praised for holding together the soil on slopes. So can knotweed be managed and perhaps in some areas kept in check? I’ll put it to you this way—do we believe we can sleep with the enemy?

A Wellesley volunteer willing to take action

Nolan has proposed a knotweed eradication trial run in which knotweed would be injected with with an herbicide. The cleared site would then be planted with mature trees to restore the landscape. Finally, follow-up spot treatment of emergent invasive plants would be done, if needed.

NRC Vice Chair Laura Robert asked if the Nolan’s method of removal was to cut the knotweed at the base, to which Schmitt said, “Yes, I believe that’s how they removed it.”

Schmitt acknowledged the breadth of research Nolan did to come to this point, and he doesn’t want to dissuade volunteers, but a big sticking point with Nolan’s plan came up almost immediately. “We can’t have volunteers applying herbicides unless they have a pesticide applicators license,” Schmitt said.

In addition, there’s concern about the idea of injecting knotweed with a weed killer. “In my mind, the real ask is do we allow herbicide application for this plant. I think that’s the bigger question,” Schmitt continued.

During discussion, the NRC Board brainstormed about possibilities other than applying poison in an ecologically sensitive area. Torch the knotweed? (We’d love a picture of Wellesley residents doing that, pitchforks in hand for good measure.) Release the goats, as has been done to manage weeds at Boulder Brook Reservation and in other areas around town? Pull up the knotweed and then pile rocks on the site to keep it down?

At one point a place of part despair, part acceptance, was reached. “I’m in agreement that we shouldn’t use an herbicide in any of these situations because it seems pointless. It is an unnecessary application, and I don’t think it leads to long-term results,” Bea Bezmalinovic said.

Ultimately, the NRC’s answer to the bigger question—that of allowing an herbicide application as part of an experiment to eradicate knotweed—was “no.” So for now, the black plastic stays.

We’ve lived to tell the tale

We know from experience on our property that the plant’s thick and deep rhizome system has to be entirely removed for any success to be claimed. After removal, something has to be planted in its place. Knotweed doesn’t go quietly, and just cutting it at the base does little to mitigate the situation. The teensiest piece of rhizome left behind will joyfully settle in and send up the next generation.

Not that we’re suggesting this for Fuller Brook Park, but the method that worked in our yard was to replace a mature, tenacious 10ft x 12ft stand of knotweed (that was inching closer and closer to our home) and incorporate that space into our lawn. First we did battle, pulling up every bit of the knotweed we could. Next, in early fall we grass seeded the area.

Bob had to run the lawnmower over hopeful knotweed shoots for literally a decade before our enemy finally ceded that 10ft. x 12ft. space. We suspect, like Optimus Prime of the Transformers fame, the knotweed is just laying dormant, waiting to explode back on the scene when the time is right. We also suspect that the knotweed has been to Town Hall and studied our plot plan. The lot adjacent to our home gets knot-weedier by the year. It’s only a matter of time before border skirmishes break out.

Our family’s experience with knotweed looms so large, my older son wrote his college essay about the invasive. Something along the lines of like knotweed, he too never gives up, thrives wherever he lands, can’t be eradicated, etc, etc. He ended up at the college of his choice, so there’s that to be said for our experiences with our foe.

As for what the town should do, I will say that time is of the essence. When is the best time to get rid of knotweed? Ten years ago. When is the second best time to get rid of knotweed? Today. And tomorrow. And every single day going forward, world without end. That’s just what it takes.

A worldwide nemesis

In Great Britain emotions run so strong around this issue that the mere hint of knotweed on a property can reduce the selling price of a home by 30%. Some mortgage providers there will flat-out refuse applications for properties where knotweed is revealed to be present. It’s been said that barristers across the pond—perhaps hired by bittersweet—got hold of the issue, put knotweed on the witness stand, and by the end of the day had drawn out a sobbing confession from knotweed that is was, indeed, plotting world domination.

Maybe such a confession wasn’t as coerced as it might seem. According to the Centre for Agriculture and Bioscience International (CABI),  the facts are that knotweed crowds out native vegetation, which contributes to limiting plant and animal species diversity (it’s actually been been described as having the biodiversity value of concrete); reduces water quality; and increases flood risk by  reducing the capacity of waterways to carry floodwater.

The Centre says that knotweed’s “stout rhizomes are notorious for pushing through asphalt, building foundations, concrete retaining walls and even drains, causing significant damage. Contaminated soil should be treated as controlled waste.”

Never, ever, ever give up

The situation sounds dire, but Wellesley mustn’t give up. Fuller Brook Park should be reclaimed, section by section. A Friends of Fuller Brook Park group once formed as a stewardship group, but their information hasn’t been updated in a couple of years. We wonder if the band might be convinced to get back together.

What’s worse, the disease or the cure?

Meanwhile, closer to home at a lovely dinner party, I asked a young college graduate working in forestry what was to be done.

“Fire,” he said.

Apparently a good old-fashioned end-to-end conflagration through Fuller Brook Park would remove knotweed and other nasties, open up the Brook Path to sunlight, and nourish the soil. We’re talking a real 1,500-degree fire here, not a brief pass over some roots with a handheld propane torch.

Somehow a scorched-earth plan along the 2.5-mile stretch adjacent to homes, schools, playgrounds, businesses, and playing fields hasn’t come up during NRC meetings. We’re guessing Fire Chief DeLorie wouldn’t entertain such a notion anyway. So it looks like knotweed eradication is going to have to be done the hard way—elimination, plant by plant.

Until then, the black plastic will remain across large parts of Fuller Brook Park, looking as attractive as great-aunt Tilly’s burgandy-and-beige crocheted afghan draped across that threadbare ancestral sofa in the basement.

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