It’s worrisome because in the United States it has proven resistant to all herbicides, is prolific and sometimes grows to eight feet tall.
It’s not the first time it’s been seen in Ontario.
Provincial specialists previously confirmed one-off appearances in separate spots in Ontario in 1966, 1978 and, most recently, in 2007 near Niagara Falls.
Cowbrough said “it was only a matter of time” before the weed turned up in Ontario, as it was already in the Ontario-adjacent states of New York and Michigan — and has been seen in all other states bordering the Great Lakes.
A few were seen in Manitoba two years ago.
It looks much like pigweed, but does not have hairy stems.
