Invasive Species

Invasive Plant Species Control

Invasive plants can disrupt natural areas like meadows, wetlands, and forests. They also negatively impact agriculture economies and can be harm to our health. A few Minnesota-specific websites with information about invasive plants, including how to identify and report, are linked below:

Invasive Terrestrial Plants (MN Dept. of Natural Resources)

Noxious and Invasive Weeds (MN Dept. of Agriculture)

Identify Invasive and Non-Native Species (UMN Extension)

 St. Louis County Public Works 2024 Invasive Plant Control plan:

• Public Works Department has hired a contractor (Prairie Restorations Inc.) who will selectively spray herbicide in the county road rights-of-way to kill wild parsnip in June and invasive knotweed in August – September. 
• If you believe that wild parsnip or invasive knotweed extends from the road right-of-way onto your property, please contact Carol Andrews at 218-625-3862 or andrewsc@stlouiscountymn.gov as soon as possible to discuss the option of having the County contractor treat the entire infestation (This is available in 2024 thanks to Minnesota Department of Agriculture Noxious Weed grant funding). If knotweed or wild parsnip are farther than 33 feet from the road center line, then they are likely on private property.
• The County will send postcards to owners of properties adjacent or very near the intended treatment locations approximately 2 to 4 weeks before treatment occurs.
• Two plants targeted for treatment by SLC Public Works:
  • Wild parsnip  -  Wild parsnip is highly invasive and if ignored can spread rapidly, developing into large monocultures that replace native animal and plant habitat. It reduces the quality of agricultural forage crops and can negatively impact livestock if ingested. The plant sap contains toxic chemicals that are activated by sunlight and can cause serious burns and blisters to human skin after contact. This makes it a threat to hikers, highway maintenance workers, ATV riders and anyone else who may use the ditches along roadways.
  • Invasive knotweed (aka Japanese/Bohemian knotweed) - Invasive knotweed is an invasive exotic plant that with hollow bamboo-like stems that can grow over 10’ high. In addition to negative environmental impacts this plant creates safety hazards by blocking site lines along driveways and road intersections. It can also negatively impact waterways, damage home foundations and pavement. The plant grows too quickly to control by routine roadside mowing. In addition, mowing can contribute to spreading the plant to new areas and lead to even more vigorous growth