By Cook County Agricultural Inspector Tim Nelson of Cook County MN - February 26, 2021

It may seem a little early in the year to be thinking about noxious weeds and invasive species but, before you know it, the snow will be gone and Cook County will become green and lush once again.  

As you go out for a drive, you may enjoy the view of all the beautiful wild flowers as they start to bloom along the sides of the roads.  However, it may not occur to you that some of those blooms might be a sign of an infestation of noxious weeds rather than innocuous roadside wildflowers.

Just what are noxious weeds, and how are they it different from other types of plants?  Noxious weeds are plants not originally from this area that can spread and cause significant harm to our native plants and natural biodiversity.  These plants may be introduced into areas either intentionally  or inadvertently but, in either case, since they are not native to this area, they lack the natural elements that would keep them in check. Consequently, many can out-compete existing native species that have developed in a balanced biodiversity of plant life and animals that rely on each other for continued existence.

Along with its pristine lake water quality and clean air, Cook County is fortunate to have minimal amounts of noxious weeds, both in types and numbers.  However, some weeds that have been introduced here need to be controlled to prevent their spread.  They include Spotted Knapweed, Canada Thistle and Tansy, which are all listed on the prohibited list through the Minnesota Department of Agriculture and must be controlled to prevent further spread.

The state of Minnesota identifies and categorizes noxious weeds in management and control lists, including weeds that should be eradicated and those that need to be controlled.  The eradicate list is made up of 16 varieties of weeds that have not yet been established in Minnesota, and so priority is given to eradicate these weeds before they can become established.  Eradicating these weeds means destroying all above and underground parts of the weeds so that they cannot grow or spread.  The control list identifies 12 varieties of weeds that have already been established in parts of Minnesota but can be controlled through a variety of means to slow or stop their spread.

Cook County is fortunate to have fewer problems with noxious weed than many other areas of the state. This is due to a combination of our unique geographic conditions, limited vectors of transmission and the work of our Cook County Invasives Team (CCIT). The CCIT is a group of local non-profits and state and federal government agency partners that work on limiting the spread of all invasive species, including noxious weeds, through early detection, awareness and education, and containment. 

Even with these efforts, it is important to be on the lookout for some of the noxious weed varieties that may not yet be present in Cook County.  One weed of concern is Common Buckthorn, a woody shrub that thrives in riparian woods with well drained soils and that can grow up to 20 or 25 feet tall.  Buckthorn can out-compete and eliminate existing native vegetation, degrade wildlife habitat, and contribute to erosion by shading out other plants that grow on the ground surface.  To identify Buckthorn, look for brown bark with elongated silvery corky projections and multiple stems at the bottom.

As we move forward into spring and summer, we should all do our part by becoming more aware of the noxious weeds and other invasive species that might impact our county.  For more information about noxious weeds and other invasive species and how to prevent their spread, feel free to browse both the Cook County Invasives Team and County Ag Inspectors web pages that can be found through the Cook County website at: www.co.cook.mn.us.  

County Connections is a column on timely topics and service information from your Cook County government. Cook County – Supporting Community Through Quality Public Service.