Scientific name: Alliaria petiolata

What Is It?

Garlic mustard is single-stalked plant, which typically grows to about 3 feet tall with small white flowers near the top. It is found in forested areas. Garlic mustard is a shade tolerant, invasive species with the capability to establish in our state. Garlic mustard is difficult to control once it has reached a site. It is native to northern Europe.

Is It Here Yet?

Yes. Garlic mustard was first identifies in Seattle in 1999, and since has been found in several locations in Washington.

Why Should I Care?

Garlic mustard out-competes native plants, changing the structure of plant communities on the forest floor and diminishing food sources and habitat for wildlife. It produces chemicals that can inhibit the growth of other plants and fungi. Garlic mustard also has been shown to cause death of larvae of certain butterfly species, which hatch on the plant.

How Can We Stop It?

Clean all gear and vehicles that have passed through known or potentially infested areas. Garlic mustard is listed as a Class A Noxious Weed in Washington, meaning its eradication is required. Garlic mustard also is on Washington’s Terrestrial Noxious Weed Seed and Plant Quarantine list, meaning it is prohibited to transport, buy, sell, offer for sale, or garlic mustard plants, plant parts, or seeds.

What Are Its Characteristics?

  • Typically grows to about 3 feet tall.
  • Small, white, four-petaled flowers grow near the top, and eventually die back and reveal slender seedpods.
  • Triangular-shaped leaves grow alternately off the main stem on short stalks and get increasingly smaller towards the top of the plant.
  • In early spring, the leaves smell like garlic if crushed.
  • When immature, the plant forms a basal rosette or low-growing cluster of kidney shaped leaves.

How Do I Distinguish It From Native Species?

During its rosette stage, garlic mustard resembles several native plants also found in the forest understory, including several plants in the Saxifrage family (e.g.Tellima grandiflora (fringe cup) and Tolmiea menziesii (piggy-back plant). Saxifrages may be distinguished from garlic mustard by its long hairs, particularly on the leaf stems. Nipplewort (Lapsana communis) may be distinguished from garlic mustard by its flowers, which are yellow instead of white. Money plant (Lunaria annua) is similar but has round, flattened seedpods.

Additional Photographs