Glossy Buckthorn: The Invasive Shrub Destroying Maine's Wetlands

Glossy buckthorn (Frangula alnus) is one of the most aggressive invasive shrubs in Maine, particularly in wet areas. It thrives in the same moist soils that support Maine's native wetland plants, outcompeting them through earlier leaf-out in spring and later leaf retention in fall. For property owners in Scarborough, Saco, Biddeford, and other coastal and riverine communities, buckthorn is rapidly transforming native wetland edges into dense monocultures.

How to Identify Glossy Buckthorn

Why Buckthorn Is Particularly Harmful

Glossy buckthorn produces abundant fruit that birds spread widely. A single mature plant can produce thousands of berries per year, each containing multiple seeds with high germination rates. The berries have a laxative effect on birds, which means seeds are deposited quickly and widely across the landscape.

In wetland areas, buckthorn displaces native shrubs like winterberry, highbush blueberry, and sweet pepperbush that provide food and habitat for wildlife. It alters soil chemistry by increasing nitrogen levels, which further favors its own growth over native species. Once established, it creates dense shade that prevents native plant regeneration.

For property owners, buckthorn infestations reduce property aesthetics, block views, and create maintenance headaches. In shoreland zones, unchecked buckthorn growth can trigger regulatory issues if it interferes with required vegetation management plans.

Effective Removal with Forestry Mulching

Forestry mulching is highly effective against glossy buckthorn. Our equipment processes the multi-stemmed shrubs down to ground level, grinding through the root crowns that would otherwise resprout after simple cutting. The mulch layer left behind suppresses germination of the abundant seed bank in the soil.

For buckthorn growing in or near wetland areas, our DEP certification for shoreland zone work means we can legally and safely operate in sensitive areas where other contractors cannot. We understand the regulations around vegetation management near water bodies and ensure all work complies with Maine's Shoreland Zoning requirements.

Because buckthorn produces such abundant seed, follow-up monitoring is important. We recommend checking the treated area the following spring and summer for seedling emergence. Young buckthorn seedlings are easy to pull by hand before they establish woody root systems, or we can do a light follow-up mulching pass if needed.