Minnesota: Noxious Weeds Spread to 8 New Counties

Palmer amaranth pigweed. Photo: Aaron Hager, University of Illinois

Palmer amaranth pigweed. Photo: Aaron Hager, University of Illinois

The Minnesota Department of Agriculture (MDA) confirmed in 2019 five species of weeds on the state’s Noxious Weed Prohibited Eradicate List for the first time in eight counties.



Weeds categorized as Prohibited Eradicate are the worst types of weeds. The law requires species on this list to have all above- and below-ground plant parts destroyed because the weeds may be harmful to public health, the environment, public roads, crops, livestock, or other property.

Collaboration with multiple agencies and organizations throughout the state, including County Agricultural Inspectors, township supervisors, and city mayors, helps the MDA successfully detect noxious weeds on the eradicate list and confirm unrecognized species.

The new finds were:

SPECIES COUNTY
Black swallow-wort (Cyanchum louiseae) Washington
Cutleaf teasel (Dipsacus laciniatus) Blue Earth
Oriental bittersweet (Celastrus orbiculatus) Nicollet
Oriental bittersweet (Celastrus orbiculatus) Rice
Palmer amaranth (Amaranthus palmeri) Houston
Palmer amaranth (Amaranthus palmeri) Lincoln
Poison hemlock (Conium maculatum) Clay
Poison hemlock (Conium maculatum) Nobles
Poison hemlock (Conium maculatum) Rice

Black swallow-wort is a viney milkweed that overtakes both sunny and shady habitats and is toxic to monarch butterflies. Cutleaf teasel forms dense monocultures in sunny grasslands and on riverbanks. Oriental bittersweet is a woody vine that overtakes forests. Palmer amaranth is a high-profile noxious weed of row crops and the MDA publishes media releases as soon as any information can be made public. Poison hemlock is a highly toxic plant that looks like wild carrot and grows in moist areas and along rights-of-way.

The MDA verifies the reports and, when possible, collects samples 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.

To report a noxious weed, contact the MDA’s Arrest the Pest line at arrest.the.pest@state.mn.us or 1-888-545-6684.

Source URL: https://www.mda.state.mn.us/noxious-weeds-spread-eight-new-minnesota-counties