Invasive plants comprise the backbone in most gardens across Canada and the globe. Commercial garden nurseries in Australia sell the exact same selection of plants that are for sale right here at home. Most of these plants trace their roots back to England or Asia and they tend to grow aggressively.
Colonizers wanting to recreate English gardens established what constitutes plant acceptability. Those gardens generally include non-native Kentucky Bluegrass lawns with beds of periwinkle, ivy, lily of the valley, honeysuckle and perhaps a multiflora rose (Rosa multiflora) which spreads aggressively and crowds out native plants.
Historically, English gardens were created as a show of wealth, status and power. The invasive, non-native plants they preferred wreaked havoc in the lands they occupied by out competing native species.
The other side to these gardens was, and still is, the drive to find a unique exotic plant that can create a focal point. Rosa multiflora from East Asia was brought to North America in the 1860s as root stock for ornamental roses originating in Central Asia and the Mediterranean. Also, think bamboo, Japanese knotweed, buckthorn and burning-bush.
The commercial cultivation, sale and widespread acceptance of non-native plants has relegated native species to the lowest level on the plant hierarchy where they are routinely mislabelled as “weeds.”
Little to no regulation of nursery plants
“The horticultural industry is the primary path for the introduction of invasive plants. However, regulations in Canada focus on plants that harm the agricultural and forestry sectors, not ones that harm natural lands. The Canadian Food Inspection Agency (CFIA) does little or nothing to regulate invasive plants sold at nurseries or the aquarium trade,” Claudette Sims, a Halton Master Gardener and co-founder of Canadian Coalition for Invasive Species Regulation (CCIPR) told rabble.ca by email.
Sims says that when highly invasive plants like Norway maple and Brazilian water weed are sold at garden centres, gardeners have no way of knowing that the plant actually harms natural landscapes and biodiversity.
Both plants are considered highly invasive, according to the Invasive Exotic Plant Species Ranking for Southern Ontario prepared by the Society for Ecological Restoration Ontario (2025). Using four categories that vary from Category 1, highly invasive, to Category 4, species to watch.
“Plants in this category [1] are a threat to natural areas wherever they occur because they disperse widely and quickly, and benefit from human disturbances. Control where possible and do not plant,” the document states.
CCIPR believes Canada must develop a more comprehensive strategy to prevent the introduction and spread of invasive species through nurseries, the pet and aquarium trade, and e-commerce channels. To protect Canada’s natural ecosystems and ensure a sustainable future that means reducing the introduction and establishment of invasive species by at least 50 per cent by 2030.
“[CCIPR] thinks high-risk invasive plants should not be sold at all and that other invasive plants require labelling to warn consumers. After all, so many consumer products are required to have this kind of information,” said Sims.
Invasive plants and an insect apocalypse
“This is important because we are currently living in an insect apocalypse. Without native plants, we’ll continue to lose insects, the basis of complex food webs,” Sims added.
Insect populations have declined 45 per cent over the past 35 years, but flying insects have experienced a staggering 70 per cent drop. This insect apocalypse means every species that relies on insects for food is affected.
The decline of bees, butterflies and other pollinators means ecosystems, crop production and food security are threatened and that threat increases exponentially when the climate crisis is factored in.
“Sadly, we don’t have any definitive lists of [high risk invasive plants] as regulations are lacking in Ontario and federally. Most regulated plants are not ones that are sold in the horticultural industry, even though that industry is the primary source for invasive plant introductions,” stated Sims.
On October 22, 2025, the Quebec Ministry of the Environment, Climate Change, Wildlife and Parks announced the tabling of a proposed regulation that would prohibit the cultivation and sale of 31 floristic invasive alien species (IAS). Interested individuals and organisations have the opportunity to participate in the consultation process for the draft Regulation until December 6, 2025.
The Quebec government considers both wildlife and floristic IAS a major threat to the province’s biodiversity. Whether their introduction is voluntary or accidental, IAS can disturb natural environments and harm native flora and fauna. The costs of controlling IAS and mitigating their impacts are high and often recurring, so the Quebec government believes preventing their introduction is the best strategy.
The draft regulation targets 31 species of plants that pose the greatest risks to Quebec’s nature, environment and economy. Penalties include:
“A monetary administrative penalty of $1,500 in the case of a natural person or $7,500 in other cases may be imposed on any person who grows or sells an invasive exotic plant species in contravention of sections 2 and 3. Every person who grows or sells an invasive exotic plant species in contravention of sections 2 and 3 commits an offence and is liable, in the case of a natural person, to a fine of $8,000 to $500,000 and, in other cases [corporations], to a fine of $24,000 to $3,000,000.”
Quebec’s Nature 2030 plan
This draft regulation is part of the Nature 2030 Plan, that aims to limit the introduction of new IAS through human activity and to curb the spread of those already in the province.
According to the 2030 Nature Plan publication:
The 2030 Nature Plan is the framework policy for biodiversity conservation in Québec. It aims to meet the majority of the new global targets of the Kunming-Montreal Global Biodiversity Framework adopted in 2022, while taking into account the realities of Québec’s regions and priorities.
The Nature Plan presents a vision for 2030 supported by four key pillars:
- Involve the First Nations and the Inuit
- Actively engage and mobilize society as a whole
- Foster discussion and synergy
- Promote access to nature
As nature is a precious ally in the fight against climate change, the actions implemented under the 2030 Nature Plan contribute to achieving Québec’s major climate objectives.
Banning invasive species from nurseries
CCIPR are working with industry partner Jeff Collins, Co-Founder of REWILD Landscapes in Ottawa, ON, to create a petition that would ban the sale of high-risk invasive plants in nurseries. Ideally, CCIPR and Collins would like to have joint implementation working with the government, the horticultural industry and the public to ban the sale of invasive plants.
“I’m creating a petition to send to the Canadian Nursery Landscape Association (CNLA) and Landscape Ontario (LO) to self regulate and stop the sales of invasive species,” Collins told rabble.ca.
Collins thought long and hard about whether to send the petition to the government of Ontario Premier Doug Ford because ultimately, they would be responsible for regulating the sale of invasive plants, but decided against it.
“The Ford government has already shown their cards regarding the Green Belt and I don’t believe they would interfere with a business’s right to sell anything let alone for ecological reasons. Nurseries and garden centres continue sales of invasive plants because the demand is there but I believe that’s because the masses are not educated in what is and is not invasive,” said Collins.
Collins wants to prove to commercial nurseries that customers don’t actually want these plants and that as the demand for native plants increases, the decline of invasive sales won’t hurt their profits.
“I know there are folks at CNLA and LO that are stuck in the past and will fight this but these organizations have a social and ecological responsibility because they are the stewards of the land who are profiting off nature. Take Ritchie’s Feed and Seed in Ottawa for example, they have created a native plant section in their garden centre and labeled invasive species with a sticker stating that this plant is invasive and speak to an associate. Incredible! I send business to them specifically because of this,” stated Collins.
Addressing invasive species through legislation
The Ontario Invasive Plant Council (OIPC) has created a list of 31 invasive plants including buckthorn, burdock, dog-strangling vine, garlic mustard, Manitoba maple, Norway maple and phragmites.
The Aquatic Invasive Plant: Best Management Practices developed by the OPIC contains 23 water plants that need to be addressed including phragmites, purple loosestrife, rough mannagrass, water hyacinth and water lettuce.
According to CCIPR member, Cathy Kavassalis, Ontario was the first province to enact a stand-alone Invasive Species Act in 2015. However, Quebec is playing catch-up and its 2025 proposed regulation demonstrates how much more there is to accomplish.
“The proposed list targets many ornamental plants that continue to move freely through horticultural trade in Ontario – species such as goutweed, Japanese barberry, autumn olive and buckthorn, all well-documented invaders. Ontario’s Auditor General called for stronger regulation in 2022 (Annual Report, 2022, pp. 389 – 413), emphasizing the need to update the province’s species list,” Kavassailis told rabble.ca via email.
“Ontario already has the legal framework in place, what’s missing is the political will to expand and modernize the list in line with current science and lessons from neighbouring jurisdictions,” she added.
Kavassalis maintains each year of delay means higher management costs and deeper biodiversity losses which could be offset with prevention – the most cost-effective strategy.
To bring all provinces into alignment with preventing the introduction and spread of invasive species, there needs to be a national framework that harmonizes species lists, risk assessments as well as data-sharing among provinces and territories.
Kavassalis believes the lesson for Ontario is not to follow Quebec, but to reclaim leadership.
“Modernize Ontario’s list, harmonize regulations nationally and ensure that prevention, not cleanup, drives Canada’s invasive species strategy,” stated Kavassalis.
As for Collins, he knows that when businesses self regulate it creates a much better public relations image than having a government force change.
“We all have a duty to the birds and butterflies and bees. Currently the City of Ottawa allows native plants up to one meter/three feet tall in the right of way and they are reimbursing homeowners for rain water catchment projects. The next things I’d like to see them do is offer funding for invasive species removal and reimbursement for installing feather friendly window decals. But! We can only fight one battle at a time so right now I’m taking on the sale of invasive plants,” he said.
Episode of Dragon’s Den Jeff Collins from REWILD was featured on:
https://www.cbc.ca/dragonsden/episodes/season-19-episode-11
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