Overview
- The Michigan Commission of Agriculture and Rural Development ordered water hyacinth and water lettuce to be listed as prohibited species effective June 19, 2026, which makes it illegal to introduce, import, sell, or distribute them in the state.
- Common buckthorn, glossy buckthorn, Callery pear, and Japanese barberry are slated to become restricted species on Jan. 1, 2028, a category that recognizes they are already established but subject to control and sale restrictions.
- Callery pear, once widely planted as an ornamental street tree, has been identified and mapped in Southeast Michigan and is cited by officials for spreading into restored wetlands and forest edges and displacing native plants.
- State officials said water hyacinth and water lettuce form dense mats that reduce water flow, harm fish and aquatic life, and can interfere with hydroelectric and water infrastructure, which drove the rapid prohibition decision.
- The order follows a scientific review and public input and aims to give nurseries, landscapers, and the public time to comply while allowing landowners to retain plants already established on their property under current guidance.