CASCO – Rona Fried spends her summers in Casco working diligently to eradicate an invasive plant, which, in the last several years, has infiltrated forests throughout the Lakes Region.

“I will be driving,” Fried said Friday, “and I will see a sprig, so I pull over and pull out my kit and cut it – and then it’s gone.”

Oriental bittersweet, a plant native to Eastern Asia, is a light brown perennial vine – with a stem 2 to 4 inches in diameter, which grows to more than 50 feet in length. It has glossy, 2- to 5-inch-long finely toothed leaves. It infests woodlands, forest edges and open fields.

From May to June, clusters of small green and white flowers bloom along the stem, Fried said. At full maturity, the plant produces red-orange berries containing seeds, which persist through the winter and are spread widely by birds or people using the branches for decorative arrangements, she said.

Fried, who grew up in Casco and is the founder and CEO of based in New York where she lives most of the year, visits her native Casco every summer. And while she tries to enjoy her free time on Pleasant Lake, getting rid of the invasive plant is at the top of her to-do list.

It’s everywhere


“It’s not just in Casco. It’s everywhere: Raymond, Sebago, Naples, Bridgton, Norway,” to name a few towns, Fried said of the plant Friday, as she prepared to snip a sprig from the invasive-covered woodland behind the post office in Casco Village.

She first learned of the bittersweet invasion nearly 12 years ago in New York, but during the past few summers in Maine, her work to eradicate the plant became top priority.

Oriental bittersweet chokes native plants, deprives them of sunlight and weakens them, she said. If nothing is done to eradicate the bittersweet, she said native plants will eventually die.

According to Fried, who eats organically and is an advocate for the environment, the plant’s growth rate depends primarily on weather conditions.

“Whether people want to believe it or not, we are in climate change. It’s making the weather in Maine and everywhere else much warmer, much wetter. Perfect conditions for invasive plants,” Fried said.

Like milfoil or invasive insects, Fried said, terrestrial invasives such as the Oriental bittersweet somehow “hitch a ride” from their place of origin and end up taking over an ecosystem.


“They have no natural enemies, or anything that naturally controls them,” Fried said of bittersweet. “They are out of control here. They bloom earlier than our native plants and die later. They have a much longer lifecycle. Nothing kills it, unless a human comes along and pulls it out.”

Effective eradication

In order to effectively kill the plant, a certain process must be followed, said Fried. And, it can take hours – even years – depending on the infestation.

“Find the root. Take a fresh cut; you can’t cut it and come back a month later,” she said. “You cut it as close to the root as possible and paint it with full-strength Roundup. And then it dies.”

While it’s rare to fully eradicate an entire area of bittersweet, as long as the area is maintained every summer, the plant will eventually be gone, Fried said.

Many residents, she said, are aware the plant exists, but have no idea how to kill it. Instead, they prune it, which only makes it grow back stronger, making future eradication efforts virtually impossible.


Identifying bittersweet is easy, she said, but killing the plant can be daunting.

“You’ve got to climb into the thick of everything and you have to cut it at the root,” she said, as she opened her tackle box where she keeps pruning clippers, a collapsible saw and full-strength Roundup, an herbicide that seeps into the roots and kills the entire plant.

If left to fester, bittersweet climbs its way to the top of a tree where it “forms a canopy and it smothers the tree and it wins,” Fried said.

‘Ignorance is bliss’

The reality, she said, is that bittersweet doesn’t grow quickly; it’s that the plants took over years ago and people aren’t stepping up to take care of it.

She hopes people will realize how “horrifying” the plant is and join her bandwagon. She said unlike in New York, bittersweet in Maine exists only in smaller patches.


When it comes to eradicating terrestrial invasive plants, “ignorance is bliss,” Fried said. “People aren’t concerned enough.”

In addition, no efforts are being made at the state level to eliminate bittersweet, she said. She said government officials only seem concerned about aquatic invasives, like milfoil.

“The DEP [Department of Environmental Protection] will never do anything about it on a homeowner’s piece of land,” she said of the bittersweet.

Maine State Horticulturist Ann Gibbs confirmed there are no efforts at the state level to eradicate bittersweet, but providing information about identification and control of terrestrial invasives to Maine residents is ongoing.

“It’s definitely a concern for folks,” Gibbs said.

“A lot of these plants have been here a long time. What I recommend to folks is, pick your battles. If there is a special place or area you want to keep clear, then focus on that; but you don’t try to clear every piece. As she [Rona Fried] experienced, it’s virtually impossible, or you need an army of people [helping.]”

Unfortunately, Gibbs said, neither the proper resources nor funding is available to combat terrestrial invasives.

“Milfoil works because there is a funded program. Funds come from boat registrations, which goes directly into that program, used specifically for that,” Gibbs said.

A woody vine called Oriental bittersweet, an invasive plant from Eastern Asia, wraps around the trees behind the U.S. Post Office in Casco.Rona Fried picks up a dead stem of the invasive plant, Oriental bittersweet, she killed earlier in the summer.Rona Fried unpacks her tackle box filled with supplies that she uses to kill off Oriental bittersweet, an invasive plant that is infiltrating Maine’s forests.

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