Invasive Plants

Barberry an example of an invasive plant.



What: The Maine Department of Agriculture, Conservation and Forestry has adopted rules (DOC) that prohibit the sale of 33 terrestrial plant species determined to meet the invasive plant criteria described in the rule.

When: The new rule went into effect on January 14, 2017. As specified in the rule, the prohibition of sales does not begin until January 1, 2018. Businesses selling any of the 33 invasive plant species have until December 31, 2017 to sell any remaining stock.

Documents: The new rules are based on comments received during the December 8 public hearing and written comments received during the open comment period. The response to comments and basis statement for these rules are public documents.

Questions?: Call Gary Fish 207-287-7545 or email

Plant List

Plants listed below are illegal to import, export, buy, sell or intentionally propagate after December 31, 2017. The ban includes all cultivars, varieties and hybrids of these plants.

Terrestrial Invasive Plant List (PDF 139KB)

Terrestrial Invasive Plant Poster (PDF 4MB) Full size printer versions (PDF 26MB) (PUB 79MB) Large files.

Species links go to fact sheets that help with identifcation and control..

Scientific Name Common Name
Acer ginnala Amur maple
Acer platanoides Norway Maple
Aegopodium podagraria Bishop's Weed
Ailanthus altissima Tree of Heaven
Alliaria petiolata Garlic Mustard
Amorpha fruticosa False Indigo
Ampelopsis glandulosa Porcelainberry
Artemisia vulgaris Common Mugwort
Berberis thunbergii Japanese Barberry
Berberis vulgaris Common Barberry
Celastrus orbiculatus Asiatic Bittersweet
Elaeagnus umbellata Autumn Olive
Euonymus alatus Winged Euonymus
Euphorbia cyparissias Cypress Spurge
Fallopia baldschuanica Chinese Bindweed
Fallopia japonica Japanese Knotweed
Frangula alnus Glossy Buckthorn
Hesperis matronalis Dame's Rocket
Impatiens glandulifera Ornamental Jewelweed
Iris pseudacorus Yellow Iris
Ligustrum vulgare Common Privet
Lonicera japonica Japanese Honeysuckle
Lonicera maackii Amur or Bush Honeysuckle
Lonicera morrowii Morrow's Honeysuckle
Lonicera tatarica Tatarian Honeysuckle
Lythrum salicaria Purple Loosestrife
Microstegium vimineum Japanese Stilt Grass
Paulownia tomentosa Paulownia
Persicaria perfoliata Mile-a-Minute Weed
Phellodendron amurense Amur Cork Tree
Populus alba White Cottonwood
Robinia pseudoacacia Black Locust
Rosa multiflora Multiflora Rose

Alternatives to Invasive Plants

What are invasive plants?

In Maine a plant is considered invasive if it:

  1. is not native to Maine
  2. has spread (or has the potential to spread) into minimally managed plant communities (habitats)
  3. causes economic or environmental harm by developing self-sustaining populations that are dominant or disruptive to native species

Invasive plants are a direct threat to what we value about Maine's natural and working landscapes. The aggressive growth of invasive plants increases costs for agriculture, can affect forest regeneration, threatens our recreational experiences, and reduces the value of habitats for mammals, birds and pollinators. Species like Japanese barberry and multiflora rose can form thorny, impenetrable thickets in forests and agricultural fields.

Invasive species are the second-greatest threat to global biodiversity after loss of habitat. Invading plants out compete native species by hogging sunlight, water, nutrients, and space. They change animal habitat by eliminating native foods, altering cover, and destroying nesting opportunities. Some invaders are so aggressive they leave no room for our natives.

History of Invasive Plant Regulations in Maine

2007 - DACF is directed by the legislature to study invasive terrestrial plants, the Commisioner appoints a stakeholders group to provide input on developing criteria for listing potentially invasive terrestrial plant species that could impact natural ecosystems. Plants evaluated using the criteria developed would be those commercially distributed and not necessarily weeds in the landscape.

2008 - The report from the commisioner appointed committee studying invasive terrestrial plants is presented to the legislature Invasive Plant Report (PDF 29KB) (DOC 56KB)

2011 - A new rule is adopted outlining the criteria for listing invasive terrestrial plants.

2015 - The Invasive Terrestrial Plants Workgroup finishes reviewing 38 plants to see if they meet the criteria set forth in the 2011 rule. Thirty-three of the 38 plants were found to meet the criteria and five did not.

2016 - DACF proposes changes to Ch. 273 Criteria for Listing Invasive Terrestrial Plants (DOC) that could restrict the sale or ditribution of the 33 plants found to meet the criteria.

2017 - DACF adopts Ch 273 (DOC).