By Katherine Nixon and Mandy Hiscocks

OPIRG is a student-funded and volunteer-driven organization based on the University of Guelph campus.  We focus on social and environmental justice, and on helping people to develop activist and organizing skills and experience.  I’m the Volunteer Coordinator there.  I’ve lived in Guelph since 1994 when I started at U of G and fell in love with the town and the rivers here.

Every year in May we gather to pull garlic mustard up from along the Speed and Eramosa Rivers, as part of the 2Rivers Festival. We teach people about the plant and show them how to pull it up properly and how to make pesto with it.  We pull up as much as we can and the City disposes of it, and then we plant native plants in the empty space in the hopes that they will thrive there instead.

Garlic Mustard is an invasive plant that was brought over from Europe in the early 1800s.  It was grown as a salad green and herb, used to treat ulcers and gangrene (and probably a lot more things that I don’t know about), and sometimes planted to prevent erosion.  Its Latin name is Alliaria petiolata and it’s in the Brassicacae (mustard) family.

It has a two-year life cycle and only flowers in its second year.  First-year plants grow low to the ground whereas the second year plants grow tall, anywhere from 30 to 130cm. The flowers are white with four petals and grow at the top, and the seed pods are long and shoot upwards. It tends to grow in transitional areas like river floodplains, forest openings, roadsides, and trail edges.  Many of these conditions are met in Guelph between the walking trails and the rivers, so we see a lot of garlic mustard in those areas.

Since garlic mustard comes up early in the spring and grows fast, it can crowd out other plants and spread very quickly.  It does this by restricting access to sunlight and also by killing fungi in the ground that bring nutrients to native plants and trees, actually changing the composition of the soil.  Pulling up garlic mustard allows for other native plants to grow, which is important because native plants are important food sources for pollinators and wildlife.  Garlic mustard hasn’t replaced these plants as a food source because it’s so new to the ecosystem here, so when native plants are replaced by garlic mustard there’s a reduction in available food and in biodiversity. 

When you learn to recognize garlic mustard you can become overwhelmed with how much there is and how impossible it seems to eradicate it.   My suggestion would be to choose an area that is important to you, that you go to often, and that is small enough to feel manageable.  It’s probably easier and more satisfying to take on an area where the garlic mustard is just starting to encroach and to work to keep it out than to go to a place that is covered in it and try to restore it.  

You can eat the whole plant – root, stem, leaf, and flower. There are lots of recipes online for salads, pestos, pasta sauces and so on

Pulling and eating garlic mustard feels like a win-win because we’re helping to restore the land; we’re getting nutrition from something very local that didn’t exploit any migrant labour, use any pesticides, or get transported anywhere using fossil fuels; and we’re not depriving other beings of food or having to worry about overharvesting a wild edible, which is a concern as more and more people are turning to foraging for wild plants.

Eating the plant also allows us to feel grateful instead of angry or annoyed at it; it’s not its fault that it’s here after all.  In its own land garlic mustard is part of a balanced ecosystem and it’s just continuing to do what it evolved to do naturally.

Doing community pulls allows us to talk about all of these things.  We also have a chance to address more complicated ideas, and to connect the concept of invasive species with settler colonialism and the responsibilities settlers have to land that is not ours and to an ecosystem, we didn’t evolve to be part of.  More and more people are becoming concerned about pollinators and want to help increase food sources and habitat for them, so these events are one way we can contribute to that effort.

At OPIRG we pull up garlic mustard to try to undo some of the damage being done to the ecosystem it’s invading, but it’s important to note that there are different ways to look at garlic mustard and at invasive species generally.  Ecologically, some people think it would be better for us not to interfere but instead to let them take over and either create a new balance or burn themselves out.  Philosophically, some people question the very ideas of “invasion” and “damage” – after all, everything moves around the planet all the time, and habitats are constantly changing, and why should humans constantly be trying to control nature?  These are important conversations that start with whether or not to pull garlic mustard and can lead to much larger questions of humans’ place in the world, the role and contradictions of environmental conservation, and the nature of evolution and change. 

You can reach Mandy at, and if you’re interested in learning more about OPIRG Guelph, go to

mandy hiscocks is a settler
from the UK who came to this continent as a child and has called Guelph home for 25 years now. she works as the volunteer coordinator at OPIRG Guelph and many years ago was a member of the Peak collective.

Katherine Nixon is a teenage community organizer living
on Anishinaabek lands. She works to provide support and solidarity in her community and beyond.

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