To prevent harm to the economy, public health and the environment, we need urgent action to curb the spread of invasive plants via the horticulture industry. Legislation is the most logical and cost-effective course of action.

Here is what we need:

  • Effective pre- and post-border invasive species risk assessments
  • Bans on the sale and movement of high risk invasive plant species
  • Labelling to identify and educate the public about lower-risk invasive plants
  • A verifiable industry-wide Code of Conduct
  • Public education including alternatives to invasive plants

Prevention is Key

The increasing numbers of invasive plants entering Canada each year are having serious ecological and socio-economic consequences. Invasive non-native species spread quickly and the cost for their removal escalates over time making management nearly impossible. Preventing their introduction and establishment in our environment with legislation is the most logical and cost-effective course of action. Canada’s legislative framework on invasive plants is fragmented. Improved coordinated regulation is needed at the federal, provincial and territorial levels.

The invasion curve shows the stages of invasive species management from pre-arrival (prevention) to long-term control. After a species is introduced, management costs increase and likelihood of eradication decreases as time passes.
Stopping the spread of invasive plants is one of the most cost-effective actions we can take. Image sourced from the Invasive Species Council, Australia.

The Time to Act is NOW – Help to Spread the Word

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We Can No Longer Afford to Ignore the Consequences

Hundreds of millions of dollars are spent to control invasive plants in Canada. In British Columbia, just six species of invasive plants cost an estimated $65 million in 2008, with a projected cost of $129 million by 2020. Additionally, there are the inestimable costs to our natural environment — our life support system.

Invasive Plants are Costing Us Millions. Illustration by C. Sims.

Invasive Alien Plant Species (IAPS) cause harm to the environment, the economy and human health. Control of these species costs millions of dollars across Canada. They impact agriculture, forestry, recreation, biodiversity, ecosystem health, and public health. The numbers of invasive plant species are steadily growing in Canada and preventative measures are essential for slowing this trend. 

Ecological Costs and Consequences

Invasive plants can:

  • Suppress or displace native plant species 
  • Disrupt essential food webs and impact wildlife 
  • Change litter decomposition, soil formation, soil chemistry and the distribution of soil organisms
  • Reduce the availability of resources, like water or nutrients
  • Impair essential ecosystem function and services, like pollination
  • Diminish native habitats
  • Reduce genetic diversity and global biodiversity
Invasive periwinkle (Vinca minor) invading Beamer Conservation Area Grimsby. Image: MaryAnne Sharpe/Shaunna MacQuarrie May 21, 2021.

Social and health consequences

Economic consequences

  • Increased hazards to human health (poisonings, allergies, dermatitis, injuries, disease – Lyme disease, West Nile virus)
  • Threats to food production
  • Diminished recreational opportunities (bird watching, hiking, camping)
  • Depression and mental health impacts associated with losses and management
  • Loss of our unique natural legacy (Indigenous cultural heritage, maple sugar production, beauty of Canadian landscapes)
  • Costs for removal or control
  • Negative impacts on agriculture, forestry and fisheries
  • Loss of revenue from tourism, hunting, fishing and recreation
  • Damage to infrastructure (e.g. drainage systems, transportation corridors)
  • Increased risks of fire, erosion, and property damage
  • Reduced property values

How Invasive Plants Arrive in Canada

According to the Canadian Food Inspection Agency (CFIA), the horticultural trade is the largest pathway for the intentional introduction of invasive plant species. Many invasive plants arrive as garden ornamentals and are sold to consumers who are unaware of their negative impacts.

Chart showing horticultural is the primary pathway for the Intentional Introduction of Invasive Plants in Canada
Pathways for the Intentional Introduction of Alien Invasive Plants. Slide from C. Kavassalis data source: Canadian Food Inspection Agency. 2008. Invasive Alien Plants in Canada: Technical Report. CFIA. Ottawa, ON

Measures to prevent the spread of ornamental invasive plants at provincial or territorial borders are inconsistent or non-existent. Ontario is the only province that employs an explicit Invasive Species statute. Other provinces have regulatory tools, such as Alberta’s Weed Control Act and Manitoba’s Water Protection Amendment Act. A very small number of invasive plants in the horticultural trade are currently regulated.

A Growing Opportunity

While restrictions on invasive plants may be disruptive in the short term, there are opportunities for innovation – including potential for expanding local markets. Innovative nursery growers can capitalize on regional botanical uniqueness. Importers
and breeders should focus on non-invasive plants that support our native pollinators, wildlife and or food production. This process can be transformative for the industry and ultimately benefit all Canadians and global biodiversity.

We must work together to stem the tide of invasive plant species. Legislation is needed now to reduce the escalating costs of management and protect our unique and precious heritage. By protecting our natural heritage from degradation, present and
future generations can continue to enjoy the economic, social, and cultural opportunities a healthy environment provides.


The Canadian Coalition for Invasive Plant Regulation (CCIPR) formed in early 2022 in response to an outcry from the public, voiced on the 28,500-member Master Gardeners of Ontario (MGOI) Facebook social media platform. A proposal to regulate plants in the horticultural trade was drafted by MGOI, a charitable organization dedicated to educating the public about sustainable gardening practices. A coalition of volunteers, representing organizations and individuals from across Ontario, then joined together around these objectives to become the Canadian Coalition for Invasive Plant Regulation. We are at the initial stages of organizing and building capacity. Individuals and organizations across Canada are invited to join and participate. Read Our Real-Life Origin Story.

Join us. Protect Canada’s Natural Legacy

Photo adapted from Helft Keitel