News Giant hogweed that can cause third degree burns and blindness spotted in Haliburton County SHARE ON: Kenny Trenton, contributor, Thursday, Aug. 10th, 2017 A giant hogweed that can cause permanent blindness has been located in Haliburton County. This is according to the Nature Conservancy of Canada, which is reporting sightings of the plant near Canarvon and Highland Grove. Central-West Ontario Program Director Kristyn Ferguson says the sap, not the plant, is dangerous. //www.myhaliburtonnow.com/wp-content/uploads/2017/08/Fergie-BadSap.mp3 Ferguson adds the weeds are generally over six feet tall, but can sometimes reach heights of over 18 feet. She suggests you wash the sap off your skin immediately if you suspect you came in contact with it. Click here to see where giant hogweed sightings have been reported. If you see one of the plants, click here to report it to the Nature Conservancy of Canada.