3 plants to watch out for while outside in Ottawa this summer

CTV News

04-06-2025

Sap from wild parsnips can cause burns. Other side effects can include blindness if contact is made with the eyes but symptoms may not appear immediately.
As you head out for a walk or a hike this summer, watch out for some plants that can turn a peaceful journey into a painful problem.
Eastern Ontario Medical Officer of Health Dr. Paul Roumeliotis dropped by CTV Morning Live to discuss three plants to watch out for in Ottawa and eastern Ontario while outside – poison ivy, wild parsnip and giant hogweed.
Poison Ivy
Poison ivy is known for its ability to cause an itchy rash. According to Health Canada, it can grow on sandy, stony, or rocky shores, and sprouts in thickets, in clearings and along the borders of woods and roadsides.
'It's a weed; it's a vine, it can grow long, and we find it everywhere,' Dr. Roumeliotis said.
'It is three leaves on a stem. If you get into contact with it, the sap is very toxic. You can put it on your skin; 24 hours later, you'll have a red rash, an itchy rash.'
The medical officer of health says symptoms will develop 24 to 48 hours after contact with the sap from poison ivy.
The inflamed areas will develop blisters, which leads to intense itchiness, says Health Canada.
Dr. Roumeliotis recommends washing any area of your skin with soap and water and use a calamine lotion.
Poison Ivy leaves
A dermatologist shares his advice on how to avoid getting a rash from contact with poison ivy this summer. (Eric Fleming / Shutterstock.com)
Wild parsnip
Wild parsnip is an invasive plant that can cause harm to humans and animals if they come into contact with it. The plant secretes oils that can cause skin to burn and blister when exposed to sunlight.
'It's a wild plant. They are called parasitic plants, in other words, they actually are in fields, all over the place, meadows – wherever it's abandoned,' Dr. Roumeliotis said. 'They kind of take over other plants and it's not good for overall vegetation.'
Dr. Roumeliotis says blisters can appear 24 to 48 hours after exposure to the sap from the wild parsnip.
'They have a sap in them and if you get in contact with the sap, basically it reacts with the sun. It's actually burning the skin.'
According to the Ontario government, you should wear protective clothing and dispose of plants carefully if trying to remove small clusters of wild parsnip from your property. Wash the rubber gloves with soap and water and then take off your clothing.
Dr. Roumeliotis says the important thing is to 'be aware' of wild parsnip to avoid contact.
The City of Ottawa is spending $298,000 this year to deal with wild parsnip on municipal property.
Wild parsnip examples
Examples of the growth stages of the wild parsnip plant. (City of Ottawa/supplied)
Giant Hogweed
Dr. Roumeliotis says the giant hogweed is a relative to wild parsnip and can grow to five metres tall.
'Just like the wild parsnip, the giant hogweed sap is quite toxic,' Roumeliotis said.
'If you get into contact with it, put it in your eye, you can cause blindness or temporary loss of vision. It can cause blisters, burning and really bad things.'
Roumeliotis said symptoms can occur within 48 hours and consists of 'painful blisters.'
According to the Ontario government, giant hogweed has a scattered distribution from Manitoulin Island to Ottawa.
'About 10-12 years ago, we got some calls from the emergency room in my area, and they were telling us these kids came in with burns and burns in their eyes and burns all over and they had played with this big plant,' Roumeliotis said.
'We did some investigations, and it was the giant hogweed.'
The Ontario government recommends hiring a professional exterminator to remove the giant hogweed from your property.