This commentary is by Judith D. Schwartz of Bennington. She is the author of three books that explore global challenges through the lens of nature, including “Cows Save the Planet: and Other Improbable Ways of Restoring Soil to Heal the Earth.”
One day I walked down the hill and glanced at the trees — the stately canopy at our property’s edge. Then I took a closer look: what I thought were crowns of maple, oak and shagbark hickory was in fact a shroud of vines, likely the Asiatic bittersweet that’s been shimmying up every trunk and limb in sight.
Our land in southwestern Vermont is far from unique in being overrun by vines masquerading as treetops. Consider kudzu, known as “the vine that ate the South.”
And now, throughout New England, you’ll see trees bent and weakened by the advancing vegetation, now little more than scaffolding for leafy vines. In western Massachusetts, the Kennedy and Burbank parks contend with the “kiwi apocalypse,” as hardy kiwi — originally introduced by garden clubs and favored by Gilded Era elite — smothers native trees, while Sudbury’s Asiatic bittersweet problem is such that groups have instituted “bittersweet removal days.” An out-of-control invasive vine scenario is often referred to as an “infestation.”
Troublesome vines like Asiatic bittersweet, kiwi, porcelain-berry, wisteria and, yes, kudzu, are generally dispersed by wildlife that eat the fruit. They are persistent: emerging from seeds, sprouting from roots, sending shoots or runners from cut stems. With fast-growing vines draped across our woodlands, our beloved broadleafs have to struggle for air and sunlight.
When it comes to unwanted plants, my go-to is Mike Bald, whose Royalton company “Got Weeds?” manages invasives without chemicals. Mike does have a grudging respect for vines, and recognizes they do play an ecological role — at least when systems are in balance.
“Vines are nature’s rehab species,” he says. “They cover bare ground, stabilize temperatures, and allow recovery from disturbance to begin.” The invasion of invasive vines, then, can be seen in part as a symptom of the damage our forests, meadows and riparian areas have sustained.
He also attributes this shift toward vines to conditions that increasingly favor climbers and creepers. He notes a study from 2006 that found poison ivy — a vine that’s native, if not beloved — grows more rigorously amid warmer temperatures and increased CO2.
While many trees suffer under weather extremes, he says vines seem unbothered by drought or wet conditions. One reason hardy kiwi flourishes in our part of the world is that it can withstand below-zero temperatures. Asiatic bittersweet’s trick is that it thrives in sun or shade, forest or city lot, is fire-resilient, and can be spread both by birds and via underground roots. This canny plant has it all covered — and not only the unwitting trees.
Are our ridgelines doomed to be eclipsed by counterfeit canopies? We can start being proactive by becoming aware of them. One challenge is that these plants drift in slowly so that you don’t notice until they’re wreaking havoc — just like I was caught unawares by what I’d initially thought were treetops. At first glimpse you assume that it’s green so it must be fine.
It’s important to bring fresh eyes to the scene. Then you can acquaint yourself with the specific vines. Once familiar with the plants, you’re more likely to catch them early, before they’re established or setting fruit, while it’s still easy to pull them out by hand. Let them dry in the sun and then dispose of them safely.
For large vines that are rooted in, get them out of the canopy to keep them grounded. Mike says to cut them at the base and flag them so you can do repeat cuttings to eradicate the vines. (Eventually the plant will exhaust its reserves.)
This way, birds — those vectors of aggressive seeds — won’t have access to the berries. And watch for seedlings, which you can yank out before they get their hold on a tree.
We should also be prepared for what’s ahead. On his travels through the region Mike has seen signs that more troublesome climbers are coming our way. “Up and down the Hudson River you can see vast stretches of non-native greenery,” he says. “River corridors, rail lines and roadways are the fingers poking northward into the heart of New England.” It’s worth knowing that kudzu has come up as far north as Massachusetts.
Mike recently came by and I showed him the faux treeline. What struck him was the hole in the forest canopy, a 100-feet in diameter circle where the trees had collapsed inward. The vines were still there, sending tendrils to the next row of trees. He had just been in the Berkshires and said this was the exact pattern he observed in Massachusetts, including in Lenox’s Kennedy Park, where the kiwi reigns.
It’s on us to keep our eye on the vines. Our local trees are worth it.
