The other day I was riding my bike and had to take a leak. I walked through the un-mowed vegetation at the edge of the road to the woods, did my thing, and went back to my ride.
The next morning I noticed a red spot on my leg that burned. I thought back and realized I had rubbed against some wild parsnip when I walked through the un-mowed area at the roadside.
Fortunately it was only a minor burn, and it’s since healed. But wild parsnip can be really dangerous. My son was weed-eating an area with wild parsnip one morning. The sap sprayed up on his arms as the sun beat down. He got severe burns and blistering of the skin. Some of those scars didn’t go away for months.
For those of you who aren’t familiar with this plant, it pays to learn it. You can save yourself a lot of pain if you can spot it and avoid it.
Wild parsnip is an invasive plant native to Europe and Asia. It’s in the same family as carrots, giant hogweed, and Queen Anne’s lace. To identify it, look for a tall plant (2-5 feet) with saw-toothed leaves and deeply grooved stems. It’s most noticeable features are its flowers, which are yellow and grow in umbrella-like clusters from June to September. You’re most likely to find wild parsnip in pastures, old fields, and roadsides.
Wild parsnip is an invasive plant. It can take over roadsides, pastures, and old fields like this one near our office.
A close-up of the leaves and grooved stem of wild parsnip.
Wild parsnip flowers are small, yellow, and grow in umbrella-shaped clusters.
The sap is what makes wild parsnip and the other plants in its family dangerous. When the sap gets on your skin (usually by rubbing against the plant), the sap reacts with your skin to make it extremely sensitive to sunlight. Essentially it causes you to get extreme sunburns even with just a little sun exposure. The burns, blisters, and welts are painful and can last for months or even years in the worst cases (you can see a picture of a wild parsnip burn in this article from CBS News).
Obviously it’s safest if you avoid touching this plant. Wearing boots, long sleeves, and long pants when you hike can help avoid accidentally rubbing against it (and also help protect you from ticks).
If you do get exposed to wild parsnip sap, you can reduce your chances of burns with a few steps:
If you want to control this invasive plant on your land, there are ways to do it. You can hand-pull it, but be very careful to protect yourself (and don’t rub your eyes! If you get the sap on, say, your gloves and then rub your eyes, the sap can get in them and damage your vision and even cause blindness). Prescribed burns can also be effective, but check local ordinances to find out if and when burning is allowed in your area. Mowing and herbicide are also possibilities. For herbicide, make sure the chemical you use is specifically labeled to control wild parsnip.
For all these control methods, it’s best to do them before the parsnip goes to seed. Otherwise a new crop of plants will be on its way. Existing seed can lie dormant in the soil for four years, so you’ll likely need to repeat your control efforts over several years to be successful.
Wild parsnip isn’t the only poisonous plant in your woods. For more information on hazardous plants, check out this factsheet from the University of Illinois Extension.