Wild parsnip, an invasive plant that can cause painful burns to people who come into contact with it, is blooming early in Wisconsin. Invasive plant experts encourage property owners to mow this plant or take other actions now to prevent its spread.
“The warm weather last week probably pushed wild parsnip to bloom. The earlier you can control it the more successful your efforts will be,” says Kelly Kearns, invasive plant coordinator for the Department of Natural Resources Natural Heritage Conservation program. “Mowing is the easiest way to prevent it from seeding – it won’t kill it but it will prevent it from spreading.”
Wild parsnip grows very successfully in habitats where soil was recently disturbed and invades prairies, oak savannas, roadsides, and pastures throughout Wisconsin. The species can be easily identified by its 4 to 6 foot stems and yellow, flat-topped, umbrella-shaped flowers that bloom from late spring to midsummer.
If allowed to go to seed, this plant can rapidly spread, forming large, dense patches. In addition to competing with native and pasture plants, the sap from wild parsnip can cause painful burns on the skin, even on a cloudy day. The burns may appear as rashes or blisters, and can cause skin discoloration for several months or even years – always wear gloves, long sleeves, and long pants if you expect to come into contact with it.
Wild parsnip can be controlled by removing the plants, mowing it, conducting a prescribed burn to kill the plant or applying herbicides. Wild parsnip can be pulled from the ground or cut with a sharp shovel 1 to 2 inches below the soil surface. If flowers are present, bag the plant material and send it to a landfill or burn it in order to prevent any seeds from spreading and colonizing new areas.
Mowing can be an effective control method if it is done during the early flower stage, before the seeds have developed. Though the plants may grow, re-sprout and re-flower, seed production will be greatly reduced. The targeted and repeated application of chemical herbicides can also limit the spread of wild parsnip. Prescribed burns conducted by trained professionals can also reduce the abundance of wild parsnip.
Wild parsnip has been documented in all 72 Wisconsin counties. Read more about this invasive in “Still Feeling the Burn [PDF],” in the June 2017 Wisconsin Natural Resources magazine. For more information regarding wild parsnip, visit dnr.wi.gov, keyword “invasives” or please check out the the UW Extension fact sheet (exit DNR).