Invasive Species | Terrestrial Plants
Garlic Mustard
Photo: Mary C Legg, Mary C Legg, Bugwood.org
Garlic Mustard
(Alliaria petiolata)
French common name: L'Alliaire officinale/ Herbe à ail
Originally brought to North America from Europe in the 1800’s as a edible garden herb, Garlic Mustard is an aggressive plant that forms dense stands in early spring, monopolizing resources and shading out native species. It is avoided by deer, who then over-browse native species, and is allelopathic - meaning it inhibits the growth of other plants around it by releasing biochemicals into the surrounding soil.
Characteristics
Life cycle: biennial herb with two different growth stages; reproduces by seed, commonly produces up to 600 seeds per plant.
1st Year Growth: dark green, kidney-shaped leaves that grow low to the ground in rosettes; leaves have scalloped margins and smell like garlic when crushed.
2nd Year Growth: tall, flowering stalks (up to 1m); triangular leaves with toothed margins that alternate along the hairy stem.
Flowers & Seed Pods: clusters of small white flowers with of 4 petals that emerge in early May; develop into long seed pods (2.5-6cm) that contain 10-20 small seeds each.
Habitat: Commonly found in forested and other partial or fully shaded areas but adaptable to a wide variety of conditions; thrives in disturbed areas.
Chris Evans, University of Illinois, Bugwood.org
Key ID Features
Rob Routledge, Sault College, Bugwood.org
Distinct garlic smell when leaves are crushed, particularly in first year.
Steven Katovich, Bugwood.org
Extensive ‘carpeting’ of ground at both growth stages in heavily infested areas.
Common Look-a-Likes
Karan A. Rawlins, University of Georgia, Bugwood.org
Wild Violets (Viola ssp):
Leaves are heart-shaped with shallow toothed margins, >1.5m tall
More prominent palmate leaf veins
Chris Evans, University of Illinois, Bugwood.org
Wild Ginger (Asarum canadense):
Each plant has 2 large velvety heart-shaped leaves and a single flower at the base
