First year plants (left) form low green rosettes while second year plants (right) can grow 30 to 100 centimetres tall with small white four-petalled flowers.
Jane Glenn | 6 May 2026
Urgent concerns about the rapid spread of garlic mustard, one of Ontario’s most aggressive invasive plants were raised at the April 27 regular council meeting.
“This species is spreading rapidly in our region and across North America and poses a serious threat to our forests, biodiversity and long-term ecological health,” council was told by local residents Michele Hunter and Rosa Pyette. A call for community volunteers was made, as well as for continued help with short and long-term remediation from the Town, the pair said.
Garlic mustard is a biennial herb brought from Europe in the 1800s for culinary and medicinal use and has become widespread across southern and central Ontario, including Grey-Bruce.
Hunter warned that garlic mustard is not just a nuisance. “It’s not just another weed,” she said. “It has a negative effect on our forest ecosystems.”
First-year plants appear as low-lying green rosettes and can be mistaken for native species such as ground ivy or violets. “In their second year, the plants grow between 30 and 100 centimetres tall and produce small white, four-petaled flowers. When crushed, their leaves emit a distinct garlic scent,” explained Hunter.
Because it has no natural predators in North America, garlic mustard forms dense stands that crowd out native plants, including wildflowers, tree seedlings and rare woodland species. “This reduces our biodiversity and disrupts natural forest regeneration,” said Hunter. The timeline isn’t very long either, she emphasized as garlic mustard infestations can double in size every four years.
The plant spreads through foot traffic, pets, wildlife, contaminated soil and garden dumping, according to Ontario’s Invasive Species Centre and the Ontario Invasive Plant Council. Each plant can produce hundreds to thousands of seeds, which can remain viable in soil for up to five years.
Garlic mustard also alters soil chemistry by releasing compounds that inhibit the growth of native vegetation. This has ripple effects throughout the ecosystem, impacting butterflies, ground-nesting birds and small mammals. “The result is a decline in overall ecosystem health and resilience,” Hunter said.
Locally, garlic mustard has been identified in parks, forests, and residential areas throughout Saugeen Shores. Efforts to combat it locally began in 2022 along the Rail Trail, where volunteers quickly realized the scale of the problem. Despite organizing weekly removal events each May over the past four years, Hunter said progress has been limited as “the number of volunteers has not been sufficient to cover all of these areas.”
A co-ordinated plan was developed with former Parks Manager Frank Burrows, prioritizing protected woodland areas such as Beiner’s Bush and the Shipley Trail.
She also outlined several ways municipalities can respond, including early detection and reporting, the mapping and monitoring of infestations and prioritizing removal in high-value natural areas. Manual removal, meaning hand-pulling plants before they seed in late spring, is the most effective control method. Plants must be bagged and taken to landfill, as composting can allow seeds to spread.
Hunter emphasized that while garlic mustard is manageable, success depends on swift, co-ordinated action. She asked council to assist by sharing information through their social media and helping with printing educational materials, as they have done in the past.
Public education and volunteer engagement are also key. “We need help with an awareness campaign,” Hunter said. “We believe that if more people were aware, we would see an increase in volunteers, which would help immensely in fighting this invasive species.”
To support outreach, volunteers have created a Facebook group, ‘The Garlic Mustard Challenge of Saugeen Shores’ and a Messenger group, ‘Saugeen Shores Invasive Volunteers.’
Still, Hunter said these platforms have not reached enough residents to meet the need. “The number of parks and natural areas in our town keeps growing,” Hunter said. “Volunteers could assist the Town in keeping these areas healthy and enjoyable for everyone.”
Additionally, Hunter urged council to consider the creation of a permanent Parks and Recreation stewardship program. Such a program would assign volunteers to specific natural areas to monitor invasive species and litter.
“By acting now, our municipality can protect biodiversity, reduce long-term costs and preserve healthy forests for future generations.”
Council members thanked Hunter and Pyette for their work and dedication and pledged to continue supporting their efforts.
