Plants from the dark side – Wild Parsnip

(Judith Cox, a Master Gardener, is the President of the Stittsville-Goulbourn Horticultural Society. Judith shares the characteristics and effects of Wild Parsnip as well as providing tips on ridding your property of this insidious plant.)

I remember the first time I went to the doctor with a weird rash that would not go away. That was my introduction to wild parsnip. At the time they did not know what it was, and many outdoor workers were coming in with it, so it was named the landscaper’s rash.

Wild parsnip is a biennial and starts out with a low rosette of leaves in its first year as the roots form and in the second year it flowers with yellow umbel flowers that look like Queen Anne’s lace flowers. The plant grows to over a meter in height and the seeds can spread easily. If the sap from any part of the plant gets on your skin and the sun shines on it then rashes will occur. These rashes start out looking like poison ivy, but they do not dry up like poison ivy. The serum in the blisters gets thicker and yellow and when it finally passes, a scar remains. Of course, some people are immune to these plants just as some are immune to poison ivy.

  • The plant can form dense stands that out-compete native plants, reducing biodiversity.
  • Stem, leaves, and flowers contain chemicals that can increase skin sensitivity to sunlight and cause severe dermatitis.
  • Wild parsnip reduces the quality and saleability of agricultural forage crops such as hay, oats, and alfalfa.
  • Chemical compounds in the plant are known to reduce weight gain and fertility in livestock that eat it.

You need to exercise caution when dealing with wild parsnip. If you are working on it try to do so on a cloudy day. When you finish wash your hands with sunlight soap as you do when you are in contact with poison ivy. I make sure to wash myself and my clothes after dealing with it. Do not let the wild parsnip in your area go to flower. Cut all the flowers off then try to destroy the plants themselves. The city will not take wild parsnip in the green bin and you do not want it in your compost so put it in a garbage bag to sit in the sun. Because I have an organic garden, I do not use chemicals to destroy the plant but if you have a large infestation it is recommended to call a professional to get rid of it. Again, err on the side of caution with this plant.

To find out more about Wild Parsnip, visit the Ontario webpage


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