It’s that time of year when fawns are growing, yards are greening, and the tall, yellow flowers resembling dill are blooming along many roads throughout Koochiching County and the state.
Wild parsnip, a weed listed as invasive, noxious and prohibited by both Koochiching County and Minnesota, continues its invasion in Borderland.
The Minnesota Department of Natural Resources describes wild parsnip as a weed that readily moves into disturbed habitats, along edges and/or in disturbed patches. It invades slowly, but once population builds it spreads rapidly and can severely modify open dry, moist, and wet-moist habitats. Wild parsnip has also been found to invade native prairies. Wild parsnip is most abundant in southeastern Minnesota, but is present in most counties in Minnesota. A native of Europe and Asia, this plant has escaped from cultivation. It is grown as a root vegetable and is common throughout the U.S.
While its invasion is worrisome, the most concerning fact is it causes phytophotodermatitis, a rash with blisters that can occur and result in scarring or discoloration when the juice of wild parsnip comes in contact with skin in the presence of sunlight — on cloudy or sunny days. People are urged to avoid contact with the toxic sap of the plant by wearing gloves, long sleeves and long pants.
Koochiching County Land Commissioner Nathan Heibel is aware of the concern about the invasive weed, and said he’s noticed in the last few days the flowers are starting to set, or form little green seeds within the yellow flower.
He said mowing areas containing the weeds — if it has not been regularly mowed throughout the summer — could help spread the seed, not eliminate the plant.
“Once the seeds are set on the plant, mowing at that point is doing more harm,” he said.
Mowing regularly to keep the plant from blooming can help limit the seed production for the next year.
As the season continues, wild parsnip will turn brown, appearing as though it is dying.
“That’s when the seeds are ready to cast out, by whatever means, wildlife, people, wind, and mowing,” he said.
Parsnip is here to stay, but its expansion can be limited by use of effective herbicides, he said.
“We will never get rid of parsnip, unfortunately, but the goal is to keep it in check from spreading to new areas,” he said.
Escort XP Herbicide is fairly effective for fall-time application, and is selective, in that it does not kill all plants, he said.
Heibel said land managers across the state see it along roadway right-of-ways.
“It’s not only a problem in Koochiching, but statewide and regionally,” he said.