Looking for Invasive Plants

Members of the Harpswell Garden Club have joined with the Harpswell Invasive Plant Partnership to identify and map invasive plants on public and land trust lands in Harpswell. The collected information will be used for education purposes and to help decide if, when and how invasive plant control may be applied.

Teams surveyed Mitchell Field, Houghton Graves Park, Johnson Field, Giant Stairs/McIntosh Lot and the rights of way along Routes 123 and 24, Mountain Road and Cundy’s Harbor Road. In May, the teams sought to identify woody plants: autumn olive, Norway maple, winged euonymous, multiflora rose, Japanese barberry, buckthorn, Asiatic bittersweet, and Japanese honeysuckles. They were also on the lookout for garlic mustard and Japanese knotweed. Later in the summer, the surveyors returned to seek out purple loosestrife, common reed, spotted knapweed, black swallowwort, Himalayan balsam (Touch me Not) and yellow iris. They also kept an eye out for more garlic mustard and Japanese knotweed.

Why worry about these invasive plants? They may crowd out valuable native plants, and they may be detrimental to native wildlife. Black swallowwort, for example, is fatal to the monarch butterfly. When a butterfly lays its eggs on this plant, the larva die of the toxins that are in the swallowwort. This plant is also toxic to dogs and horses. Here are some photos of invasive plants we found in Harpswell.