You may have heard about non-profit or environmental organizations recruiting members of the public for "garlic mustard pulls". But what exactly are those plants, and why are they bad?
Garlic mustard is found in all of the Great Lakes states, with the highest density located in the eastern half of the country (as shown in the below EDDMap, 2019). This invasive species was introduced from Europe as it was used in food (e.g. salads, pestos, soups etc...), soil erosion control and for medicinal purposes. Garlic mustard got its name from the smell it emits when the leaves are crushed (a strong garlic like scent) and its resemblance to the mustard plant. This plant was able to spread out of control due to reasons such as one garlic mustard plant being able to produce up to 8000 seeds in one season, it emerging earlier than many native flowers, lack of a natural predator and is not preferred by deer as a food source. Impacts of this flower include reducing area biodiversity in the understory of forests, shades out native wild flowers such as trillium's and spring beauty. They have allelopathic compounds that may limit the germination of seeds of other species.
Garlic mustard takes two years to complete its life cycle. During the first year, plants form basal rosettes close to the ground, and can over winter in that form, all the while continuing to perform photosynthesis. During the second year, it will grow taller (up to 4 ft tall), and produce small, four petaled flowers. Leaves have a slight triangular shape and are sharply toothed around the edges. They typically flower in Michigan during the month of May.
If you have this plant on your property, there are a few management strategies you can employ, and management should focus first on satellite populations and for larger infestation, from the peripheral part of the infestation moving inwards towards the epicenter. Hand pulling can be effective for small populations, and the entire plant (including the roots) needs to be pulled up and bagged immediately. For larger infestations, herbicide may be more effective. Detailed management options summarized by the State of Michigan can be found here.
For more information:
Center for Invasive Species and Ecosystem Health. 2019. Garlic Mustard. Date Accessed: May 22, 2019. Website: https://www.invasive.org/browse/subinfo.cfm?sub=3005
EDDMapS. 2019. Early Detection & Distribution Mapping System. The University of Georgia - Center for Invasive Species and Ecosystem Health. Available online at http://www.eddmaps.org/; last accessed May 22, 2019.
MDNR. 2019. Garlic Mustard (Species Profiles and Reporting Information). Website:
The Nature Conservancy. 2019. Journey with Nature: Garlic Mustard. Date Accessed: May 22, 2019. Website:
Shikha Singh is the coordinator for the JLW CISMA. She has a BSc. in Biology from University of Western Ontario, and her master's and PhD at Michigan State University from the Dept. of Fisheries and Wildlife. Her areas of expertise include water quality, water policy, invasive species, education/outreach and public speaking.