Nestled on a hillside next to the Cross River Reservoir in Pound Ridge, New York, the woodlands of the 43-acre Armstrong Preserve and Education Center offer hiking trails, rock formations, and a large vernal pool. It is one of many local gems owned and managed by the Pound Ridge Land Conservancy.
But not all their woodlands look so great. “It’s all invasives. It needs to be burned,” says Land Steward and Educator Krista Munger half-jokingly.
Invasive plants like Japanese barberry are a challenge here, but the large vines on the trees are an even bigger problem. The vines, especially the invasive oriental bittersweet, weigh down and strangle trees, eventually killing them.
Apart from killing the trees, the vines make the other invasive plants worse. Invasive plants thrive and spread rapidly in sunlight. When the trees die, they can’t shade the ground anymore. If the vines kill the trees, the invasives will take over.
“Our forest management plan recommends remediation here, but we still don’t know what we are going to do,“ explains Munger.
That’s why PRLC decided to cut vines here. Cutting the vines will keep the trees alive, slow the invasives’ spread, and give Munger and her team more time to figure out their options for addressing the other invasive plants.
Vines had totally strangled many trees at Armstrong Preserve, even young, strong trees like this hickory.
Armed with bow saws and loppers, Munger and a small team of volunteers began cutting the vines. They planned to cut vines over a one-acre area.
But right away they hit an obstacle. “The hardest part of this project was the barberry surrounding the vines, “says Munger. The dense invasive shrubs made it hard to get close enough to the vines to cut them.
Invasive barberry bushes surround this oriental bittersweet vine. The dense shrubs made it hard for Munger and her volunteers to approach and cut the vine.
To counter the barberry, Munger recommends cutting vines in the winter. “We were on show shoes. They help you get over the invasives.”
Munger didn’t limit her vine cutting to the invasive oriental bittersweet. Grapevines, while native and beneficial to wildlife, can harm or kill trees too. The trees at Armstrong had such poor health that saving them required cutting all vines, including the grapevine.
This white ash tree had both oriental bittersweet and grapevine smothering it. Munger had to cut both vines to save the tree.
Vine cutting takes time, but Munger has a tip to save you some effort. “Cut the vines in a way that’s very obvious so that you don’t get to a vine and then find that it was already cut”, she says. “Cut high and low so you can see from afar that they’ve been cut.” You can also mark your progress with flagging or spray paint.
Like a lot of invasive plant control projects, cutting vines isn’t a once and done effort. The vines often resprout. “Sometimes we’ve seen 10 sprouts coming off a single cut vine,” says Munger. The sprouts can even reattach to and revive the old vines remaining in the trees.
Revisit your vine cuttings periodically to check for resprouts. You can deal with them with a second round of cutting, or by carefully using herbicide. Sometimes deer help by browsing the sprouts, but don’t count on them for control.
Thanks to hard work from Munger and her volunteers, the Armstrong Preserve’s trees will recover and grow again. The team will return in five years to remove more vines, but in the meantime, Munger sums up her feelings on the current project this way: “It feels like a ‘done’.”