What could be a pleasant spring hike could leave you very disappointed. Garlic mustard (Alliaria petiolata) has been found within the Red Wing city limits in the last couple years. If you also appreciate native wildflowers and wildlife, this is one invasive species that should be “nipped in the bud” before it becomes established. Like most invasive species it is most efficient and cost-effective to eliminate small populations before they expand and become widespread.
The good news is that the garlic mustard populations within Red Wing are small, and if addressed now might be controlled or contained.
Garlic mustard is easy to identify. The herbaceous biennial stems are 12 – 36 inches tall and are the only plant with four white petals blooming in wooded areas and edges in May. The leaves are round/scalloped and the stems smell like onion or garlic when crushed. It is critical to pull and destroy the plants before they go to seed in early to late May as garlic mustard seeds remain are viable in the soil for 5-7 years. Small patches can be pulled by hand (be sure to get the full root) burned or chemically treated.
Garlic mustard is a Minnesota Department of Agriculture Prohibited noxious weed. It poses and ecological threat to high quality woodlands upland and floodplain forests, not just into disturbed areas. Invaded sites undergo an ecological decline of native herbaceous cover within 10 years – often garlic mustard is the only plant that remains. Garlic mustard alters habitat native insects and thereby birds and mammals. Some studies in New England found that trees did not reproduce in areas taken over by garlic mustard.
According to the Minnesota DNR website “species on the Prohibited noxious weeds listed must be controlled, meaning efforts must be made to destroy all propagating parts and prevent seed maturation and dispersal, thereby reducing established populations and preventing reproduction and spread as required by Minnesota Statutes, Section 18.78. Additionally, transportation, propagation, or sale of these plants is prohibited.”
If you see garlic mustard in your woodland address it now. If not, next year you will be guaranteed even more. For more information see http://www.dnr.state.mn.us/invasives/terrestrialplants/herbaceous/garlicmustard.html