Harmful Angelica plant spreads in New Brunswick

The Angelica sylvestris, an invasive plant species which can cause blisters and skin rashes, is spreading to new ground in the Fredericton area.

The plant, which is currently in flower and grows to over two metres, is taking over patches of disturbed ground, ditches, and other wet areas around the city.

As a native of Eurasia, Angelica lacks natural predators in Eastern Canada. Steve Heard, a professor of plant ecology at the University of New Brunswick, said Angelica can squeeze out native plants.

"A single plant could make hundreds of thousands of seeds," he said. "Many of our invasives in their native habitat in Europe or Asia or wherever they come from may be attacked by dozens or hundreds of insect species."

"And yet here they've come over without their enemies and specialist insects don't recognize them as food or don't like them, haven't evolved to deal with them as a food…they grow unchecked."

The New Brunswick Invasive Species Council said the province seems to be at the centre of a national Angelica invasion.

While the plant was first reported in Fredericton and Cape Breton, it has now also been found in Quebec and Ontario.

New Brunswick's weed management officer cautioned that Angelica has a chemical in the sap that can cause skin rashes and blisters when exposed to ultraviolet light, including sunlight.

Gardeners should weed out the plant on a cloudy day, wearing gloves, and wash with soap and water afterwards, the officer said.