Sale of Invasive Exotic Plants Soon to Be Banned in Quebec

On October 22, 2025, Quebec’s Ministry of the Environment, Climate Change, Wildlife, and Parks (MELCCFP) announced the tabling of draft regulations aimed at prohibiting the sale and cultivation for distribution of 31 invasive alien plant species.

According to the ministry, the draft regulation is part of a preventive approach that aims to regulate activities likely to introduce and spread invasive alien species in Quebec, namely the production and trade of these plants. The 31 species targeted are those that, in the government’s opinion, pose the greatest risks to Quebec’s nature, environment, and economy.

Quebec Stands Apart

Almost all (90%) of the Canadian provinces and US states south of the Canadian border, or 52 out of 58 entities, have at least one law or regulation relating to harmful plants with a list that includes more than one species. Of these 52 provinces and states, 43 have a law or regulation that applies to plants that are harmful to the environment. These laws and regulations focus primarily on prohibiting the sale and purchase, cultivation and propagation, and transportation of such plants.

Quebec has a section (95.1) in the Environment Quality Act that allows it to prohibit the sale of harmful exotic plants, but it has no effect since no species is duly regulated. The MELCCFP bill, if adopted, will correct this shortcoming.

Which Species Should Be Banned?

The MELCCFP asked me to propose a list of species that should be regulated as a priority. I first examined the lists of species prohibited from sale elsewhere on the North American continent. I quickly realized that they were not very useful for making proposals. In my opinion, and that of several researchers who have analyzed them, these lists lack logic and rigor. They differ greatly from one state to another and are inconsistent, even between neighboring states. They are also much more reactive than proactive, in that they mainly prohibit species that are already well established in the territory, which limits their effectiveness.

Species at Moderate or High Risk

After careful consideration, I therefore proposed to first regulate, with a few exceptions, species that pose a moderate or high risk to Quebec’s natural environment. I based my proposal primarily on the risk analyses in two books on invasive plants that I published in 2019 and 2022, which were extensively revised and reviewed by experts. I therefore proposed a total of 26 species as a starting list.

The MELCCFP has adopted most of my suggestions (see the complete list here), including plants that are obvious choices, such as giant hogweed, water chestnut, and Japanese knotweed, even though they will be difficult to find commercially. The list is not only reactive, it also includes species that are absent or very rare in Quebec, such as Carolina fanwort, kudzu, and umbellata oleaster, but which could soon become established or proliferate as the climate becomes milder. The ministry has gone a little further than I had anticipated with a list of species that, in my opinion, pose a low to moderate risk, but whose sale is prohibited as a precautionary measure. These are mainly aquatic plants, such as yellow floating heart, parrot’s-feather, and brittle naiad.

Why Not Ban Norway Maple?

While the draft regulation has been generally well received, several people have expressed surprise on social media at the absence of Norway maple from the list. Isn’t it an invasive tree? Certainly, but the problem with this tree is less its propensity to establish itself in urban woods (which is a reality) than the fact that too many have been planted in cities, putting the urban forest at risk in the event of a disease or insect outbreak affecting its health. The Norway maple remains a useful tree because it is resistant to pollution, and not all cultivars are fertile. A number of them could be removed from the market, but more research is needed before an informed decision can be made.

In general, regulated plants in Quebec’s neighboring states elicit little reaction from the ornamental horticulture industry, except in the case of Norway maples. Nursery growers have a lot of them in stock, and it takes time to produce them—like it or not, this is a concern that must be taken into account. 

The MELCCFP toyed with the idea of banning it for a while, but a few botanists (Jacques Brisson from the University of Montreal, Alain Paquette from the University of Quebec in Montreal, and myself) opposed the ban, mainly because it is one of the few trees that can grow in the city under difficult conditions. It therefore helps to mitigate the effects of heat islands locally. However, all three of us agree that it should not be planted near natural woodlands, which can be regulated at the municipal level.

Choosing Your Battles

For my part, I have always maintained that we must choose our battles carefully. Including Norway maple in this very first draft regulation could spark an environmental controversy that we can do without at a time when science is receiving less favorable coverage than before. Based on some American experiences, the media attention given to a possible ban on Norway maple overshadows the fundamental objective of the regulation, which is to ensure that plants that are harmful in more ways than one are removed from the market once and for all.

This regulation is, after all, only a starting point, and if it is accepted, perhaps one day the Norway maple will be next. In the meantime, helping researchers develop sugar maple cultivars (for example) that are resistant to urban living conditions would be an excellent way to find non-invasive replacement trees.

Would you like to comment on the proposed regulation? In addition to this blog, you can participate in the consultation on this project until December 6, 2025.

Thank you to Jacques Brisson and Alain Paquette for their comments on this text.