Invasive Plants

What is an Invasive Plant?

An Invasive Plant is simply a plant that is not native to a particular environment that is likely to cause harm to the native ecosystem.

Why are invasive plants bad?

Invasive plants have the potential to cause economic and environmental harm. They often lack natural predators and diseases in their invaded habitats that limit their numbers in their native habitats, giving them an advantage. Left un-checked, invasive plants can grow and spread rapidly, pushing out and overwhelming native species in the process. This rapid growth can also degrade agricultural land, restrict space for recreational activities, and impact property values.

Why are native plants better?

Native plants are species of plants that can be found naturally in a given area. Native plants have adapted to the unique conditions of their natural environment and so have the many insect and animal species that inhabit the same areas. Once invasives take hold over a particular area, they out-compete the native plants for space, sunlight, water, and other nutrients. If the native plants disappear, then so do food sources, nesting habitats, and areas of shelter for our many species of native animals and insects.

What invasive plants are here in Freeport?

Here is a list of the invasive species that have been identified and reported on iMapinvasives, a public database. The data is submitted by users and may not reflect all the invasives in Freeport:

Japanese knotweed – Reynoutria japonica
Japanese Barberry – Berberis thunbergii
Asiatic Bittersweet – Celastrus orbiculatus
False Spiraea –Sorbaria sorbifolia
Multiflora Rose – Rosa Multiflora
Rugosa Rose – Rosa rugosa
Norway Maple – Acer plantanoides
Honeysuckle Shrubs (various) – Lonicera spp.
Colt’s Foot – Tussilago Farfara
Glossy false buckthorn – Frangula alnus
Climbing nightshade – Solanum dulcamara

Here is a complete list of invasives in Maine, maintained by the Maine Natural Areas Program (MNAP)

The iMapInvasives network maintains a map of invasive plant reports across the state, including Freeport. See the reports here.

How to identify invasives?

Before attempting to remove a plant, it’s imperative to correctly identify the species. Some common species in Freeport to look for:

Japanese Knotweed (Reynoutria japonica)

Photo: Maine Natural Areas Program

Key Characteristics: Resembles bamboo, heart- or spade-shaped leaves, small white flowers in finger-like clusters, hollow stem, zig-zag shaped branches. More Information: Maine Natural Areas Program, Invasive Plants, Japanese Knotweed

Asiatic Bittersweet (Celastrus orbiculatus)

Photos: Maine Natural Areas Program

Key Characteristics: Woody vines that wrap around mature trees and climb into the canopy. Green to orange fruits ripen to bright red in autumn. More information: Maine Natural Areas Program, Invasive Plants, Asiatic Bittersweet

Multiflora Rose, a.k.a. Rambler Rose (Rosa multiflora)

Photos: Maine Natural Areas Program

Key Characteristics: perennial deciduous shrub, groups of 5-11 leaflets with toothed edges. Flowers white to pale pink, each approximately 1-inch wide. Blooms in June. Usually has stout, curved thorns. Similar native rose species exist in Maine, but native rose species have pink flowers.

The MNAP maintains a photo gallery of some other common invasives found throughout the state: Maine Natural Areas Program, Invasive Plants, Photo Gallery of Invasive Plants

How to report invasives and why should I?

If you spot an invasive plant, you can report it on the iMapInvasives database.

Monitoring and reporting invasive species on your property or around town is a great help to natural resource professionals and other members of the community. Tracking the spread of invasive plants between areas is critical to their management and efforts to eliminate them. The longer that treatment is delayed, the worse and more expensive the problem gets.

How to remove invasive plants?

The method of removing invasive plants should be specific to the targeted species. MNAP provides guidance on removal methods for a variety of species: Maine Natural Areas Program Invasive Plant Fact Sheets

Take measures to protect yourself while working with potentially harmful plants, such as wearing gloves, glasses, and using the proper tools for the job. Continue to monitor the area following removal to ensure that no seeds or roots left behind lead to new growth.

Any vegetation that you remove should be properly managed to ensure that seeds do not spread. Place all material on a section of tarp, pavement, or pallet to dry and decompose for a few weeks. Alternatively, the vegetation can be burned (with a proper permit). Avoid putting any live vegetation into compost. More general information provided by Friends of Acadia: How To Remove Invasive Species - Friends of Acadia

The Freeport Recycling Center is currently unable to accept any invasive plant matter, as it is unable to be composted. The Riverside Recycling Facility in Portland accepts invasive plant matter for a fee. More information: Riverside Recycling Facility

Consider hiring a landscaping professional. List of licensed companies providing invasive plant management services: List of Licensed Companies Offering Services for Control of Invasive Terrestrial Plants : Got Pests? : Board of Pesticides Control: Maine DACF