In 2022, five Prohibited Eradicate species were confirmed for the first time in five counties
The Minnesota Department of Agriculture (MDA) - with assistance from County Agricultural Inspectors, township supervisors, and city mayors - helps protect the residents of the state from the negative effects of noxious weeds. A noxious weed is an annual, biennial, or perennial plant that is designated to cause harm to public health, the environment, public roads, crops, livestock, or other property.
There are four categories of noxious weeds: Prohibited Eradicate, Prohibited Control, Restricted, and Specially Regulated. The highest priority weeds are Prohibited Eradicate. To prevent these species from becoming widespread throughout the state, the law requires Prohibited Eradicate species to have all above and below ground plant parts destroyed.
Collaboration with multiple agencies and organizations throughout the state helps the MDA successfully detect priority noxious weeds and confirm unrecognized species. In 2022, five Prohibited Eradicate species were confirmed for the first time in five counties:
Brown knapweed (Centaurea jacea) Carver
Common teasel (Dipsacus fullonum) Carver
Japanese honeysuckle (Lonicera japonica) Hennepin
Palmer amaranth (Amarannthus palmeri) Freeborn
Round leaf bittersweet (Celastrus orbiculatus) Crow Wing and Mower
Brown knapweed is a perennial with small pinkish purple flowers that grows in sunny, disturbed areas. Common teasel has spiny, stiff flowers and seedheads; it prefers sunny, open habitats such as roadsides or pastures. Japanese honeysuckle is a perennial vine with fragrant yellow flowers. Palmer amaranth is a high-profile noxious weed of row crops. Round leaf bittersweet is a woody perennial vine with bright red fruit; it was reclassified to Prohibited Control on January 1, 2023.
The MDA verifies the reports and collects voucher samples when possible, for the official University of Minnesota herbarium records. As the regulatory agency for managing noxious weeds, the MDA also helps local governments with weed management and enforcement of the Minnesota Noxious Weed Law. The MDA provides training to the County Agriculture Inspectors (CAIs) while the CAIs enforce the Minnesota Noxious Weed Law.
Local governments provide a great service to the State of Minnesota by enforcing the Noxious Weed Law. With more people trained on weed identification, looking for noxious weeds, and reporting infestations to the MDA, Minnesota can respond quickly and limit the spread of new infestations.