Asiatic bittersweet climbs a tree on the Harpswell Heritage Land Trust’s Curtis Farm Preserve. (BECKY GALLERY PHOTO)

Why is it important to make way for native plants? Our birds and bees depend on native plants for their survival. Many species have evolved over centuries to utilize specific plants for food and shelter.

The monarch butterfly has adapted so the caterpillars can tolerate the toxins within our native milkweed’s leaves. These toxins help the caterpillars and butterflies survive predation from birds. Without the milkweed on which to lay eggs and feed newly hatched butterfly larvae, the monarch could become extinct.

In similar ways, other insects, birds and animals are dependent upon various native plants for survival. Native berries meet their nutritional needs. The insects themselves are food for birds, especially for baby birds in need of soft, easily digested food. A caterpillar suits this need, and it takes thousands of caterpillars to feed a single nest of baby birds until they are fledged.

Some plants “from away” adapt so well to their new homes that they become invasive. They grow fast, leafing out earlier than native plants in the spring and keeping their leaves later in the fall. Their natural enemies are missing from the local habitat, allowing them to spread unchallenged.

These characteristics create conditions in which the native plants are crowded out, lacking the space, water and sunshine they need to thrive. Many invasive plants grow in thickets that overwhelm the native plants. (These thickets of invasive plants also harbor larger-than-average populations of ticks!)

What happens when our native plants are gone? Insects disappear, and with them, so do birds. Our pollinators disappear, and with them, our food crops.

A thicket of Japanese barberry crowds native vegetation at Potts Point prior to removal by the Harpswell Invasive Plant Partnership. (BECKY GALLERY PHOTO)

What can we do to prevent this potential disaster? Provide areas for our native plants to thrive. Remove non-native plants from our landscape, then select native plants to enhance our home’s landscape.

One group of dedicated volunteers has been at work for several years in Harpswell doing just that: reducing the numbers of invasive plants in our town. The Harpswell Invasive Plant Partnership was organized in 2014 to educate our neighbors about the need to control invasive plants. Each year, HIPP organizes efforts to reduce the density and numbers of invasive plants in town.

This partnership of community groups (Harpswell Heritage Land Trust, Harpswell Conservation Commission, Harpswell Garden Club, Mitchell Field Committee and Harpswell Town Lands Committee), with interested individuals, has made a sizable dent in the invasive plants found in Harpswell.

Original efforts concentrated on several Harpswell Heritage Land Trust preserves, as well as rights of way along our public highways. Properties maintained by the Harpswell Garden Club have been successfully tended to reduce the invasive plants there. Our Town Lands Committee is working to remove invasive plants from several town properties, including the Devil’s Back Trail on Orr’s Island. The Mitchell Field Committee has largely cleared autumn olive on that property, and greatly reduced bittersweet and honeysuckle as well.

Invasive Asiatic bittersweet, Japanese barberry and shrub honeysuckle have been addressed. Autumn olive and garlic mustard are also targeted, along with several infestations of black swallow-wort and multiflora rose. The HHLT preserves at Otter Brook, Johnson Field, Potts Point and Curtis Farm have benefited annually from multiple work dates. Progress is evident to visitors to the preserves.

For a closer look at the work led by the Harpswell Invasive Plant Partnership, a nature walk with HHLT’s Priscilla Seimer and HIPP volunteer Becky Gallery is scheduled for 10 a.m., Saturday, June 11, at Curtis Farm Preserve, 1554 Harpswell Neck Road.

Several invasive plants will be identified, and areas where work has been done to make way for native plants will be noted. There are also opportunities to help control invasive plants. Check the Harpswell Anchor’s calendar for our scheduled work dates.