Margaret Gerber, director of conservation at the Brunswick-Topsham Land Trust, pins predator lady beetles to the base of infested Hemlock stands at Crystal Spring Farms on May 31. John Lichter photo

Have you had the displeasure of meeting Japanese barberry? 

After realizing the widespread issue of invasive plants, Sarah Wolpow, a certified master gardener and local permaculture designer, scrambled to find solutions.

Sarah Wolpow leads an invasive plant removal workshop at Neptune Woods on Oct. 24. Lydia Coburn photo

“From tiny yards in Brunswick to large estates in Harpswell and West Bath, nearly all my clients’ lawns are crowded by invasive plants that play a major role in habitat destruction,” Wolpow said. 

Native maple trees provide habitat for over 200 species of butterflies and moths, whereas invasive Norway maples support fewer than 10 species. With fewer pollinators, there are also fewer caterpillars. To put this into perspective, a chickadee needs approximately 5,000 caterpillars to successfully raise one brood of chicks.

Invasive species are on the rise, not just in the Midcoast. Culprits like vinca, Japanese pachysandra and English ivy have consumed miles of real estate statewide, choking out native vegetation. 

According to Wolpow, 95% of lawns consist of invasive monoculture plants. The goal is to create a lush, green landscape; however, she said without proper treatment or cooler temperatures, “that remains a pipe dream.”

For the first year, the Brunswick-Topsham Land Trust launched biweekly invasive plant removal workshops. Under Wolpow’s guidance, trail corridors obstructed by multiflora rose were cleared, allowing wildlife to return. 

Based on the pilot program’s success, the nonprofit aims to educate more members in 2025, including newcomers and those who have battled invasive plant issues for decades. 

Sarah Wolpow leads an invasive plant removal workshop at Neptune Woods on Oct. 24. Lydia Coburn photo

Invasive plant management

Everyone seems to have a pesky plant they dislike.

Sarah Wolpow leads an invasive plant removal workshop at Neptune Woods on Oct. 24. She demonstrated how to identify and remove pesky species for good. Lydia Coburn photo

The invasive removal workshops focus on woody species, outlining methods for year-round removal and prescribed treatment.

Common nuisances include Asiatic bittersweet, shrub honeysuckle, glossy buckthorn, autumn olive and burning bush. However, some homeowners face one-off struggles. 

Unquestionably, Wolpow can’t address everything in the three-hour slot, so she often encourages participants to contact the Maine Department of Agriculture, Conservation and Forestry for further information. 

Given BTLT’s proximity to the coast, it’s home to many ecosystems, ranging from freshwater tidal zones to sandplain grasslands. Invasives, an ever-growing silent threat that erodes these natural resources, shift the landscape without proper management. 

Teamwork makes work lighter, and invasive removal is no exception. The workshops also serve as volunteer days, where attendees learn about identification while helping tend to the land trust’s more than 3,300 acres.

Sam Thomason, BTLT stewardship manager, was critical in starting the program. He emphasized that while prevention — such as checking shoes and equipment for seeds or plant material to reduce the risk of spreading — is the most effective approach, herbicides can also be valuable tools for treatment.

“We teach best practices,” Thomason said. “We perform targeted herbicide applications and manual removal methods — excavating root systems, cutting stems at ground level and gradually depriving the plants of carbohydrates. The goal is to increase participant awareness. Identification is not always absolute, and we remind folks that it’s better not to treat anything at all than to treat the wrong thing accidentally.” 

Aiming ‘to educate and assist’

Thomason has found that the workshops have achieved two primary goals: to engage and educate the public while also assisting in managing the land trust’s conserved properties.

“It takes a community effort to keep our landscape resilient,” Thomason said. “Knowledge is power, and there is no time like the present to start tackling invasives.” 

As Thomason noted, many Mainers own trail systems that connect to waterfronts, forests or farmland. He hopes that continued sessions will help reduce invasive species, allowing for an increase in native plants, pollinators and clearer corridors. 

“Expanding efforts isn’t just about gaining new volunteers,” said BTLT Communications and Operations Manager Lydia Coburn. “It’s about fostering a sense of empowerment. It’s overwhelming to feel like you’re the only one who cares enough to make a difference — until you join a workshop and see that others share the same values.” 

Tiny lady beetles investigate their new home — an eastern hemlock tree at Crystal Spring Farm in Brunswick — after traveling from Pennsylvania on May 31. One beetle can be seen as a black dot on the end of the clothespin. John Lichter photo

What about invasive species that attack trees?

While the workshops focus solely on plants, insect species, such as the hemlock woolly adelgid, threaten trees lining neighborhoods and land trust properties.

Last week, Margaret Gerber, BTLT’s director of conservation, presented at the Topsham Public Library. She discussed the adelgid’s impact on native tree populations, implications for ecosystem services and current treatment distribution across the state.

The conversation also emphasized the significance of citizen science. Community members have contributed the majority of reports on the hemlock woolly adelgid, enabling the Maine Forest Service to monitor its spread and establish quarantine zones to prevent further movement. 

Enter: Sasajiscymnus tsugae, a predator beetle federally approved as a biological control. 

In collaboration with the Freeport Conservation Trust, BTLT ordered 10 colonies containing 100 predator beetles last May. Beetles were released at Crystal Spring Farm in Brunswick and Tarbox Preserve. 

They were pinned to the lower branches of trees to encourage them to move upward as they matured. The goal was to establish a local breeding population of predator beetles to help control the adelgid population, complementing a broader regional effort.

“Freeport-Brunswick-Topsham area represented a missing link in connectivity,” said Gerber, acknowledging that many other coastal had already begun adelgid treatment. “Forest ecosystems are dynamic, and predator beetles are tiny and mobile. Tracking success presents a challenge. While this isn’t a silver-bullet solution, with patience, there will (likely) be results.” 

Different from invasive plants, chemical and soil amendments may work for individual trees but are impractical for large-scale forests due to widespread pesticide use’s high costs and environmental impacts.

“All 30 guests at the library event were locked in,” Gerber said. “It’s good news. There are tangible actions collective groups can and are taking to help slow the spread of HWA and, in turn, protect the unique services our forests provide. 

To register for the final invasive plant removal workshop of the season at Androscoggin Woods from 10 a.m. to 1 p.m. on Nov. 14, visit btlt.org/event-registration.