Alliaria petiolata

Photo: Keir Morse

Synonyms: Alliaria alliaria, Alliaria officinalis, Erysimum alliaria, Sisymbrium alliaria

Common names: garlic mustard, hedge garlic, Jack-by-the-edge

Garlic mustard (Alliaria petiolata) is an herbaceous biennial forb (family Brassicaceae) that was first detected in 2020 and 2022 in two isolated streamside localities in southern and northern California. Native to Europe and northern Africa, this species has naturalized in central and eastern Asia, Australia, New Zealand, and many parts of North America. Garlic mustard grows as an understory herb of woodlands and forests, forming a loose rosette of kidney-shaped leaves in its first year and bolting to flower in its second year. Stem leaves are lanceolate and toothed; flowers are white with four petals; seeds are small and can be easily spread. Plants can grow to over 1 m at flowering. Garlic mustard can be differentiated from other similar plants by its leaf shape and the strong garlic odor of its foliage.  It is an aggressive invader of moist woodlands and forests, where it outcompetes and overtops native understory vegetation. Roots and foliage appear to have allelopathic properties that further impact surrounding plants. Individual plants can produce from 600 – ca. 7000 seeds. This plant is listed as a noxious weed in several states in the eastern USA, as well as in Washington, Oregon, Utah, and, more recently, California. It was probably originally introduced as a culinary herb.

Cal-IPC Rating: Moderate — Alert?

CDFA Rating: A*?


Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.

Weed Management Notes

No Weed RIC Management Notes are available for this species. Check for information on other species in the genus on the Weed RIC site.

Cal-IPC Newsletter Articles

Cal-IPC Symposium Presentations

Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.

Other Alliaria petiolata Information

  • Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.
  • CalPhotos - Images of plants taken mostly in California.
  • Calflora - Distribution map and records of this species in California.
  • EDDMapS - Distribution of this species in North America.
  • GBIF - Global distribution information.
  • USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.
  • Additional photos

    Alliaria petiolata_growth habit (mature)_ChrisMcDonald
    Alliaria petiolata (garlic mustard) growth habit (mature). Photo: Chris McDonald
    Alliaria petiolata_leaf (young rosette)_ChrisMcDonald
    Alliaria petiolata (garlic mustard) leaf (young rosette). Photo: Chris McDonald
    Alliaria petiolata_growth habit (young rosette)_BryceRyals
    Alliaria petiolata (garlic mustard) growth habit (young rosette). Photo: Bryce Ryals