1120 SW 5th Avenue, Suite 1000, Portland, OR 97204
Garlic mustard is a cool-season herb that originated in Europe and Asia. European settlers probably brought it to North America to use in cooking and medicine.
Garlic mustard's greatest threat is to native woodland wildflowers. It dominates deciduous and mixed canopy forests and displaces most native understory species by producing large numbers of tiny seeds and secreting chemicals from its roots. These chemicals may prevent other plants from thriving, which in turn leads to reduced plant diversity and less forage for deer and other wildlife.
Garlic mustard seeds move easily along streams and roads, and readily colonize disturbed soil. Hiking boots and vehicle tires are well-documented as a means of transporting these seeds. Be sure to clean boots and tires before leaving infested areas.
Environmental Services is working with other jurisdictions and neighborhoods to control the spread of garlic mustard in the Portland area.
Areas treated in 2013 and garlic mustard growth phases