Maine Terrestrial Invasive Plant “Do Not Sell List” Ongoing Review Update

by Gary Fish, State Horticulturist, Maine Department of Agriculture, Conservation and Forestry (DACF)

When Chapter 273, Criteria for Listing Invasive Terrestrial Plants was adopted in January 2017, the final section of the rule prescribed a five-year review of the listed species. A representative stakeholder committee has been assembled to assist the DACF with the review process. That committee (see member list at article end) has held two meetings so far and will meet again on May 27th.

After starting with 171 species (see criteria below), the initial list has been whittled down to 81 plants that will be considered for evaluation and 31 additional plants that might go on to further review.

  • The initial list of 171 species was assembled using:
    Species from the Maine Natural Areas Program Advisory List of Invasive Plants
  • Plants suggested by committee members
  • Species that have been submitted by the public using the Maine Invasive Plant Nomination Form (link is below)
  • Climate shifting species of high impact (identified by the work of the Northeast RISCC Network out of UMass Amherst),
  • Plants regulated by other Northeast states, or
  • Plants known to invade rare or sensitive habitats.

The committee will only consider species that are either available for sale or are known to hitchhike with plants offered for sale.

The plant review process involves an extensive literature search to help determine if the species or it’s cultivars and hybrids will truly be invasive, likely invasive, or potentially invasive in Maine.

Chapter 273 prescribes specific criteria that a plant must meet to be listed. The species:

  • Must be non-native to Maine
  • Must rapidly grow, establish, and spread in minimally managed habitats
  • Must have the biological potential to spread widely across spatial gaps
  • Must have the biological potential to exist in high numbers or large colonies in minimally managed habitats, and
  • Must be able to displace native species in minimally managed habitats

Once the plants have been evaluated for invasive potential, the committee will finalize a proposed list of species to be included in the Chapter 273 rules. The committee will also determine if any cultivars or hybrids proposed for exemption should be removed from the Chapter 273 list.

Proposed rule changes including additions or deletions to the prohibited plant list, will be published and available for public comment at the end of the year. As with the original rules, a phase-in period of at least one year will be included to allow newly listed plants to be sold out of inventory.

Opportunities for participation
While the stakeholder committee will be doing the bulk of the work to assemble, review and prepare a proposed list of species for inclusion on the prohibited plant list, there are numerous ways for you to be heard. Below are four ways you can participate in the process:

  1. Do you have a species in mind that you think should be evaluated for inclusion on the prohibited plant list?  Submit the species using the Maine Invasive Species Nomination Form available on our website.
  2. Is there a new or existing cultivar or hybrid of a species on the current prohibited list that research shows is not invasive? Submit the Request to Exempt a Specific Cultivar paperwork available on our website.
  3. Contact a committee member to discuss a particular species and how its inclusion (or exclusion) on the prohibited plant list might affect you.
  4. When the proposed rule is published for public comment, be sure to review the proposal and submit your comments to We want to hear from you whether you are in support, against or neither for nor against the proposed rule changes. The Department will respond to every comment before the rule is finalized. In some cases, if substantive comments are submitted suggesting changes, the proposed rule may be revised and re-advertised for public comment. The only way for us to know how the proposed rule affects you, is if you tell us!

The Stakeholder Committee
The stakeholder committee is comprised of a variety of individuals from industry, government, non-profit and educational institutions that represent different organizations affected by the development, implementation, and enforcement of the prohibited plant list.

Invasive Terrestrial Plant Stakeholder Review Committee
President of the Maine Landscape and Nursery Association or designee
Ryan Russell, Land Plans Inc., President of the Maine Landscape and Nursery Association
Representative from a production Nursery
Jake Pierson, Pierson Nurseries
Representative from a retail nursery
Randy Martin, The King’s Gardener
Representative from a land trust/land management community
Amy Soper, 7 Lakes Alliance
Representative from the production forestry sector
Kyle Burdick, Baskahegan Company
Representative from DACF – Natural Areas Program
Molly Docherty, Director, Maine Natural Areas Program (MNAP)
Representative of a university or college with ornamental horticulture experience
Matt Wallhead, Ornamental Horticulture Specialist, University of Maine Cooperative Extension
Representative from either the Maine Department of Transportation or a municipal public works
Kyle Rosenberg, Bath City Arborist
Representative of DACF- Horticulture Program
Gary Fish, State Horticulturist

Finally, this is meant to be a totally transparent process. If you have any questions about this effort or would like to see how the “sausage” is made, please send me an email at or call 207-287-7545. You can also stay up-to-date by checking our webpage at There will not be a final proposal until the end of this year at the earliest.