Garlic Mustard – Alliaria petiolata

Invasive Species

Normally when we talk about Muskoka’s wildlife and flora the focus is on preservation. We’d like to break that trend by talking about the Garlic Mustard plant. Garlic mustard is an invasive herb native to Europe. It was brought to North America in the early 1800s for use as an edible herb and has a strong, distinctive smell similar to garlic. It has escaped into the wild and is now one of Ontario’s most aggressive forest invaders.

Garlic mustard flowers - photo by Wildman Steve Brill

Garlic mustard has two distinct life stages over its first two years. In the first year, it grows only a cluster of leaves shaped like a rosette, while a strong root system develops. Plants that survive the winter produce flowers and seeds in their second year. Stands of garlic mustard can double in size every four years.

Garlic Mustard impacts the growth of native flowers such as Trilliums and Trout Lilies. It’s interference also threatens several of Ontario’s species at risk, including American ginseng, drooping trillium, false rue-anemone, hoary mountain mint, white wood aster, wild hyacinth and wood poppy.

If you find garlic mustard, please contact the Invading Species Hotline at 1-800-563-7711, or report a sighting online at