Mowing the state highway rights of way is in full swing after the wet spring delayed Minnesota Department of Transportation maintenance workers from starting the job earlier. MnDOT crews mow approximately 45,000 acres of land annually.

MnDOT, like other landowners in the state, is required to control plants on the Department of Agriculture’s restricted noxious weed list. Mowing is one way MnDOT controls them. Many of the plants seen along roadsides display vibrant colors when in bloom, but to the trained eyes of MnDOT’s roadside vegetation crews, they are invasive and a threat to native plants, animals and ecosystems.

“We want a diverse plant population on our roadsides because it’s healthier to have different kinds of plants and grasses,” said Tina Markeson, roadside vegetation supervisor. “When invasive species take over, it causes issues in the long run.”

Markeson cited purple loosestrife as an example of an invasive plant that competes with native species. The invasive plant can form dense stands that replace native plants needed by wildlife for food and habitat, she said.