Notes in a related report explain:
The goal of management is to prevent garlic mustard from producing new seeds.
Most first year seedlings and rosettes will die naturally, so management efforts should be focused on second year plants. Second year plants are easy to distinguish from first year rosettes in late spring once their stems elongate in May and they begin producing white flowers. First year rosettes will not have long stems or flowers and lay close to the ground. In summary, small infestations can be managed with vigilant pulling of second year plants every year prior to seed production or with careful application of glyphosate (e.g. Roundup) during the late fall or winter when most native species are dormant.
We now know that viable seeds can develop on any garlic mustard plants that have already flowered, even after the plants have been pulled. For this reason, we no longer recommend burying pulled plants. Plants should be bagged in plastic, tied up, and removed.
So check out what it looks like and PULL it out (including the roots) wherever you see second-year Garlic Mustard plants!
Other events to look forward to include The Green Fair on June 13 and Huron River Day on July 13 and other workdays. See the newsletter for details.