It's like something out of a horror film: A pretty plant that was once the darling of backyard gardens has escaped to wreak havoc on a community near you. It grows tall enough to dwarf adults and is armed with toxic sap that burns human flesh.
Giant hogweed (Heracleum mantegazzianum) is an invasive plant species that has gone viral in more ways than one. It looks like an overgrown Queen Anne's Lace, reaching up to 15 feet tall, but it can cause phytophotodermatitis, a chemical reaction on skin due to sun exposure.
Not only has it been the subject of numerous public health alerts, but it is also being feverishly tracked across the country by amateur botanists and media sleuths alike.
However, medical experts and nature lovers urge parents not to keep children indoors. “I just think the price of that fear is too high,” says Richard Louv, author of Last Child in the Woods: Saving our Children from Nature Deficit Disorder.
Still, the plant has a reputation as a magical lure to children because of its stature. “It's very Alice in Wonderland,” parenting blogger Bethany Lee says. What's more, the huge stalks and their hollow stems are said to remind kids of peashooters and swords.
Online forums are bursting with parents trading warnings about the plant. And forget dancing babies. One of the hottest YouTube videos is a WorkSafeBC mini-documentary on the weed, with shots of oozy burns on victims, including a young boy's face.
Just when every health advocate is encouraging young people to turn TVs and video games off and get outside, along comes a new scourge: West Nile. Lyme disease. Fire ants. Giant hogweed has been slumbering in cottage country and even nurseries, but the spate of news reports makes it feel as if it is new, and that nature is out of control.
In Ontario, callers are flooding the invasive species hotline run by the Ontario Federation of Anglers and Hunters and the Ministry of Natural Resources with questions. “We're getting at least 50 calls a day,” says Francine MacDonald, the OFAH's invading species program manager, in Peterborough. “We have three people staffing the lines full-time.”
However, there are few reported cases of injury, says Howard Shapiro, Toronto's associate medical officer of health. “Sometimes people like a dramatic story. It almost sounds like, in some portrayals, that these plants are stalking the streets and taking people down.”
Phytophotodermatitis rarely requires serious medical attention. “Most of these cases resolve on their own; you don't have to go to the hospital,” Dr. Shapiro says. In the medical literature, he found only one case he would describe as extreme: A case of a 10-year-old boy in Ireland who needed a skin graft after suffering burns from a run-in.
Dr. Shapiro, a father of two, suggests balancing the medical risks with common sense. “It's more a matter of just being aware where your kids are going to be playing and having an idea of what's there,” he says. “Which I think you'd do anyway, with poison ivy and poisonous berries.”
Nature lovers say the plant isn't hard to avoid. Ms. Lee, an Orangeville, Ont., mother and hiker, says parents who instill good hiking etiquette in their children – don't stray from the path, leave it as you found it – won't have too much to worry about.
She adds that parents should be careful when pulling over at the side of a country road to get a look at horses or cows. Giant hogweed likes the damp terrain of the ditches between your car and the fence.
Katie Krelove, a director at Toronto's High Park Nature Centre, an outdoor education non-profit running summer camps, says hogweed has not been spotted in High Park yet, but in the case of poison ivy, she and her fellow instructors teach children what to look for. “If you have a general appreciation of nature, you can learn to not see everything as a blur of green,” she says. “You can pick things out.”
Mr. Louv, the director of the American advocacy group the Children and Nature Network and the honorary chair of its new Canadian sister group, Child and Nature Alliance, takes a more adventurous approach. He suggests Boy Scout groups could be trained to safely remove giant hogweed. “It could be an outdoor adventure,” he says. It would certainly keep nature competitive with other childhood thrills such as video games and action movies. Mr. Louv says his childhood love of snakes led to his nature advocacy.
He believes it's all about comparative risk. He lines up childhood obesity, among other effects of an indoor lifestyle, against nature's worst villains nature. “Nature is risky,” he says. “But there is also a huge risk in raising kids under house arrest.”
