Menominee Tribal Enterprises Controlling the Spread of Garlic Mustard

Menominee Tribal Enterprises is treating selected areas of the forest to control Garlic Mustard, an invasive plant species threatening the forest. Garlic mustard is a biennial, a plant with a 2-year life cycle, that aggressively invades woodlands if left uncontrolled. Once established, Garlic Mustard dominates the site and out-competes native plants, reducing the diversity of the forest and inhibiting natural forest regeneration.

Treatment consists of hand-pulling mature, seed-bearing plants and spraying young plants with Glyphosate, a broad-spectrum herbicide approved for forest use by MITW Environmental Services. The herbicide has a low toxicity to animals, has a short half-life and quickly breaks down when in contact with the soil. Signs will be posted near treated areas to assist people in avoiding gathering in these areas while treatment is underway. Herbicide treatment will be restricted to roadsides where possible during the growing season to minimize the impact on native species. Garlic Mustard remains green year round, so some areas will be sprayed during the late fall and early spring when native plants are dormant and not susceptible to effects from the herbicide.

Treatment is underway along Highway 47 from Dutchman Tower west to the Reservation line, and also along some of the interior forest roads near Dutchman Tower. This is the second year of a major effort along Highway 47, and significant progress is being made in reducing the seed-bearing population of Garlic Mustard in that area. A newly discovered infestation is being treated between Potato Patch Road and Crystal Springs in the northeastern part of the forest. A small infestation near Crow Settlement was also discovered this summer and is being treated and monitored to contain the spread of Garlic Mustard. Menominee County is treating a similar infestation along Highway 55. Treatment will occur periodically throughout the summer and early fall.

Other control measures are also being investigated, including logging restrictions and temporary forest road closures in heavily infested areas. Each Garlic Mustard plant produces up to 8,000 seeds that are easily carried to new areas by vehicles travelling along infested roads. Tribal members can assist in reducing the spread of Garlic Mustard by avoiding the posted and treated roads where possible. They can also assist Forestry staff in monitoring the forest for new infestations and alerting staff if they find Garlic Mustard along roadsides or in the forest. Garlic Mustard seeds are common in the ditches along Highways 47 and 55, so people are advised to avoid walking, driving, or digging within the right-of-way along those roads because the movement of soil from those sites carries a high risk of moving Garlic Mustard into new areas.

Contact MTE Forestry at 799-3896 for more information on Garlic Mustard identification, details on control measures, and maps of areas of known infections.
To learn more about Garlic Mustard, visit Michigan State University Extension

1st -year Garlic Mustard rosette		2nd -year Flowering Garlic Mustard plants
Photos courtesy of Michigan State University
Map courtesy of Menominee Tribal Enterprises