Beginning Saturday, Quebecers will be prohibited from consuming marijuana in public.
But the law permits cities to adopt their own bylaws allowing people to smoke cannabis in specific public areas where no children are present.
As of Jan. 1, Quebecers under 21 years old will no longer be allowed to legally consume marijuana.
The previous Liberal government had set the legal age at 18.
A Quebec group representing cannabis growers, the Association quebecoise de l’industrie du cannabis, said the law pushes the most vulnerable consumers to the black market.
The Canadian Press