Noxious black henbane taking root in Calgary

A member of the nightshade family, black henbane is classified as a noxious weed and causes a rash if it comes in contact with exposed skin.

Black henbane, an invasive and toxic plant species, is becoming more common in Calgary green spaces, thanks in part to the weather.

The weed is listed as noxious under Alberta’s Weed Control Act. It has a yellow flower with purple veins but is poisonous to humans and animals, and can be deadly if ingested.

The city’s pest management team says 311 calls for the plant have increased this year.

“Last year we had 93 reports for the whole year, this year we are at 73,” said Sarah Vardiel, Integrated Pest Management Technician with the City of Calgary. “The City’s mandate is to control the spread of it so if people find it can let us know.”

While it’s too early to say if there will be a higher total number of calls, the dry weather has created conditions for the toxic weed to spread.

“Weeds tend to be better competitors in poor conditions,” Vardiel explained. “So, when we’re having very dry conditions, those weeds just tend to pop up and out-compete those native species.”

Calgarians who find black henbane on their property are encouraged to remove the plant, but need to dispose of it in their black bin rather than the green compost bin.

“We don’t want this in our green carts, particularly because those go to a compost facility and we don’t want to be spreading this weed around through compost later on,” said Vardiel.