Gardens of Canadian Grass

Hershey stopped producing chocolate in Smiths Falls, Ontario, six years ago. The work went to Mexico, but the factory remains, along with reminders of the glory days: A sign that once directed school buses delivering children for tours.  A fading, theme-park-style entrance that marks what used to be the big attraction — a “Chocolate Shoppe” that sold about $4 million of broken candy and bulk bars a year.

The once ever-present sweet smell of chocolate is gone, too. In the high-ceiling warehouse, where stacks of Hershey’s bars and Reese’s Peanut Butter Cups once awaited shipment, the nose now picks up a different odor: the woody, herbal aroma of 50,000 marijuana plants.

Clinical, climate-controlled rooms with artificial sunlight house rows upon rows of plants at various stages of growth. In the “mother room,” horticulturalists use cuttings to start new plants. The “flowering rooms” are flooded with intense light 12 hours a day to nurture nearly grown plants in strains with vaguely aristocratic names like Argyle, Houndstooth and Twilling.

The new owner of this factory, at 1 Hershey Drive, is Tweed Marijuana. It is one of about 20 companies officially licensed to grow medical marijuana inCanada.

A court ordered the government to make marijuana available for medicinal purposes in 2000, but the first system for doing so created havoc. The government sold directly to approved consumers, but individuals were also permitted to grow for their own purposes or to turn over their growing to small operations. The free-for-all approach prompted a flood of complaints from police and local governments.

So the Canadian government decided to create an extensive, heavily regulated system for growing and selling marijuana. The new rules allow users with prescriptions to buy only from one of the approved, large-scale, profit-seeking producers like Tweed, a move intended to shut down the thousands of informal growing operations scattered across the country.

The requirements, which went into effect in April, are giving rise to what many are betting will be a lucrative new industry of legitimate producers. The government, which will collect taxes on the sales, estimates that the business could generate more than 3.1 billion Canadian dollars a year in sales within the next decade.

“It’s just so rare that you have an industry that’s growing but which has a huge established market,” said Chuck Rifici, Tweed’s chief executive. “A year ago, if you asked me if I’d be working while looking at thousands of pot plants, I would never have thought that would be the case.”