I remember that - the old Molson Brewery right by the highway. 
Legend has it that the pants were grown in the brewery's massive tanks, and that the growers were able to use the controlled environment in the tanks to maximize lighting, increase CO2 levels and administer fertilizers to grow (what the cops said at the time) 'Super-Pot'. The whole thing fell apart when a disgruntled worker blew the whistle on the place. 

A large, secure space with available industrial power, loading docks, and adjacent to a 400-series highway. Those guys were about 15 years ahead of their time!