The following information submitted by Claudia Koslosky.

While these plants may be beautiful, they are highly invasive and will crowd out native plant species and habitat, in turn changing the ecosystem. If you see them on your property, they need to be obliterated. NOW, while it’s in bloom and before it goes to seed, is the time to remove it (or have it removed).

While this information is from the MN DNR, it’s the best explanation I’ve found about how best to rid your property of any purple loosestrife: Controlling Purple Loosestrife

Purple Loosestrife is RESTRICTED in the state of Michigan

Prohibited and Restricted Species

Some invasive species are legally designated by the State of Michigan as either “prohibited” or “restricted.” If a species is prohibited or restricted, it is unlawful to possess, introduce, import, sell or offer that species for sale as a live organism, except under certain circumstances. The term “prohibited” is used for species that are not widely distributed in the state. Often, management or control techniques for prohibited species are not available.The term “restricted” is applied to species that are established in the state. Management and control practices are usually available for restricted species. Michigan’s Natural Resources Environmental Protection Act (Part 413 of Act 451) established the list of prohibited and restricted species, which is regularly amended by Invasive Species Orders.