SafePlants

Garlic Mustard (Alliaria petiolata)

Alliaria petiolata, commonly known as Garlic Mustard, Hedge Garlic, or Jack-by-the-hedge, is a flowering plant belonging to the mustard family, Brassicaceae.

Considerations for Pets

• This plant contains sap that emits a garlic-like odor when crushed.

Considerations for Children

• Historically, Garlic Mustard was brought to North America for cooking purposes.

Taxonomy and Nomenclature

• Scientific Name: Alliaria petiolata (Bieb.) Cavara & Grande
• Family: Brassicaceae (also known as Cruciferae)
• Synonyms: Alliaria officinalis Andrz. ex Bieb., Alliaria alliaria, Arabis petiolata, Sisymbrium alliaria, Erysimum alliaria L., Alliaria officinalis Andrz. ex M. Bieb.
• Dutch Common Name: Look-zonder-look
• Taxonomic Rank: Genus Allium

Distribution and Habitat

• Native to Europe, western and central Asia, and northwestern Africa.
• Introduced to North America.
• Frequently found along hedgerows and wood margins.

Ecological Role

• Garlic Mustard is considered an invasive, nonindigenous species, particularly in North American woodlands.
• It is recognized as a noxious weed.
• It is known to affect microbial communities through the exudation of allelochemicals.
• Can outcompete native species.

Morphological Characteristics

• Herbaceous, biennial forb.
• First-year plants form basal rosettes.
• Second-year plants bolt and flower.
• Flowering form can reach up to 1 meter (3.3 ft) in height.
• Small white flowers with four petals.
• Long, linear fruits.
• Leaves are stalked, triangular to heart-shaped, and coarsely toothed.

Growth Habits

• Biennial: first year consists of a small rosette of leaves, the second year it becomes a little-branched plant.
• Flowers from April to June, and seeds ripen from June onwards.
• Not frost tender.

Interactions with Other Organisms

• Shown to impact soil bacterial communities.
• Affects mycorrhizal colonization and community structure in other herbaceous plants.

Quirky Facts

• The genus name Alliaria is derived from the genus Allium (garlic or onion) and the Latin suffix "-aria," indicating a connection, alluding to the garlic-like odor of the crushed plant.
• Garlic Mustard was originally introduced from Europe as a food plant.

Further Information

• USDA’s National Invasive Species Information Center
• RHS (Royal Horticultural Society)
• Flora d'Italia
• Bugwood.org (Michigan State University)