NY1's Ruschell Boone has the details of the first marijuana production facility in city history. She filed the following exclusive report.

You wouldn't know it from the outside, but a Queens warehouse has been turned into a marijuana farm.

Contractors are still building the facility, but behind these walls, thousands of plants are already growing across two floors for use as medical marijuana beginning in January.

Owner Bloomfield Industries gave us a first look at renderings. When completed, the plant will have 230,000 square feet of space, the equivalent of four football fields.

"It will be five floors," said Colette Bellefleur, chief operating officer of Bloomfield Industries. "Four will be grow, and one floor will be manufacturing and production."

New York is the 23rd state to legalize medical marijuana. The first crop in Queens was planted this fall and will be harvested in a few weeks.

It's not widely known, but state law bans medical marijuana from being smoked. So the marijuana grown in Long Island City will be processed on site, turned into vapors, oils and syrup, and sold under the brand name Allayent.

"We have other brands that will be available later, but those are the first three that we are going to make available," Bellefleur said.

Bloomfield is one of five companies that won state licenses to grow and sell medical marijuana, but the Queens plant will be the city's only growing site. In January, the company will open four dispensaries, in Manhattan, Syracuse, Buffalo and Nassau County.

Doctors and patients in the program must be registered with the state, and the marijuana can only be prescribed for certain debilitating diseases.

"So there aren't going to be people coming and buying marijuana at a retail outlet and sitting out in parking lots," Bellefleur said. "These are medical buildings where patients are coming in and out."

About 100 people will work at the Queens plant, from horticulturalists to scientists and security guards. The company says the marijuana plants are being monitored 24/7, with staff on site and security cameras.

"So that you can track what happens to that plant in every stage," Bellefleur said.

Medical marijuana generally is not covered by insurance, and Bloomfield has not yet announced what it will charge patients.