The Minnesota Department of Agriculture this year has made two changes to its noxious weed list:
- The emergency listing of Conium maculatum (poison hemlock) to the Prohibited Eradicate List; and
- The movement of 25 cultivars of Japanese barberry from the Specially Regulated list to the Restricted List.
Poison hemlock underwent extensive evaluation in 2017 and was listed immediately this year because of its high toxicity and distribution throughout the state.
The barberry cultivars had been placed on the Specially Regulated list in 2015 as part of a three-year production phase-out. As of January 1, they are Restricted Noxious Weeds in the state, and are illegal to sell and propagate.
State regulated noxious weeds are defined by three categories: Prohibited Noxious Weeds, Restricted Noxious Weeds and Specially Regulated Plants. Prohibited Noxious Weeds are placed on one of two regulatory lists – Prohibited Eradicate or Prohibited Control. Prohibited Eradicate species must have all above- and belowground parts of the plant destroyed. Prohibited Control plants must be prevented from spreading propagating parts. Restricted Noxious Weeds are widely distributed in Minnesota and the importation, sale and transportation of their propagating parts are prohibited. Specially Regulated Plants have the potential to cause harm and have specific management plans or rules that define the use and management for the plants.
Listed species go through a rigorous evaluation to determine their invasiveness, difficulty and cost of control, benefit and injury or harm it may cause to humans, livestock and the environment. Each species is reevaluated every three years, and with the exception of emergency listed species, the Noxious Weed List only changes every three years.