An hour's drive south of Canada's capital, past snow-covered pine forests and farmland, Chuck Rifici is growing marijuana at an old Hershey's factory.
He plans to sell it for medical use under a new government scheme starting on April 1 that will ban home cultivation in favour of large commercial greenhouses.
Rifici's start-up Tweed is one of only six companies so far to earn a licence to grow from Health Canada, and will be the first in the world to be publicly traded on a stock exchange.
Security is airtight - as required by the new federal regulations. Staff must swipe ID cards to enter or leave a room, and the facility in Smiths Falls is under constant video surveillance.
"It's like manufacturing inside a bank," Rifici said. "But otherwise, it's just like any other horticultural operation."
Inside, workers wearing lab coats and hair nets are constantly pruning the plants. Heat, humidity, carbon dioxide, air flow, nutrients feeding and light are monitored and controlled by sophisticated software.
Hershey's used to make chocolate here, but the factory closed six years ago, after five decades in operation.
Tweed, with almost C$10 million (HK$70 million) in "seed money", plans to distribute its marijuana across Canada for medical use.
When renovations are completed, the Tweed factory will contain 30 grow rooms containing 1,300 plants each, as well as a "mother room" for seedlings.
The use of marijuana for medicinal purposes was effectively legalised in Canada in 1999, and has been expanded through a series of court challenges.
According to government figures, more than 37,350 Canadians have prescriptions for medical marijuana.
Health Canada originally tried supplying the drug itself, growing it in an abandoned mine shaft in the far north, but its marijuana was widely panned as weak.
Thereafter, nearly 30,000 home-based growing operations were allowed to crop up. But local officials complained about a lack of monitoring, and police worried about an increase in crime.
All of these small gardens will be replaced by fewer but larger commercial operations. Health Canada is reviewing 450 applications for the new licences.
"This is a brand new industry created by government regulatory changes, and growth is expected to be massive," said Rifici, citing government estimates that the number of users will grow to 450,000 by 2024.