Invasive species: Garlic mustard

February 24, 2023

Garlic mustard (Alliaria petiolate) is an herbaceous invasive plant that was introduced to North America in the 1800s. Brought to North America to serve as a medicinal plant and to help with erosion control, garlic mustard is originally from Europe and Asia. Since it has been brought to North America, garlic mustard has been reported in 38 states but is frequently reported in the Northeast, Northwest, and the Midwest.

Garlic mustard is a biennial plant. Biennials are plants that require two growing seasons to complete their life cycle. During a biennial’s first year they grow leaves, stems and roots then go dormant over the winter. In a biennial’s second year they produce flowers and seeds before dying. Garlic mustard seeds can remain viable years after they drop to the soil. Seeds can spread to new areas with help from the wind, runoff water, and human or animal activity.

Also known as the Poor Man’s Mustard, Hedge Garlic, and Garlic Root, garlic mustard smells like garlic when it is crushed. The leaves of garlic mustard are triangular and heart-shaped with toothed edges. During the second growing year, garlic mustard develops white four-petal flowers that cluster at the top of the plants’ stalks and usually bloom in late April through early June. Garlic mustard plants can grow up to three feet tall.

Like many other invasive species, garlic mustard emerges earlier than native plants in the spring. This means garlic mustard can out-compete native plants for nutrients, sunlight and moisture. In addition to this garlic mustard harms native plants by changing the soil chemistry which alters the underground fungi network connecting native plants.

Interested in learning more, check out these links:

Would you like to help us control garlic mustard's spread?

We will be hosting a few garlic mustard pull days in the spring. We’d love it for those who are available and willing to smell like garlic to join us! Keep an eye out for details as we get closer to spring.