Hydroponic tomato plants are planted at Lufa Farms' new greenhouse, located atop an office building in Laval, Quebec.
Hydroponic tomato plants are planted at Lufa Farms' new greenhouse, located atop an office building in Laval, Quebec.

Montreal-based Lufa Farms, which built the world’s first commercial urban rooftop greenhouse in early 2011, has unveiled its second greenhouse in neighboring Laval.

The 43,000-square-foot greenhouse, which opened Sept. 23, sits atop a new office building 20 miles northwest of Montreal.

It’s expected to triple the cultivation capacity of Lufa’s first rooftop greenhouse, which produced 70.5 metric tons (77.7 tons 155,425 pounds) of fresh produce last year — from arugula to white eggplant — without the use of synthetic pesticides, herbicides or fungicides.

Greenhouse director Lauren Rathmell said the additional space allows Lufa to offer a wider range of fresh vegetables year-round, including more than 20 specialty tomatoes such as pink cherry, striped german and cherokeepurple.

The new greenhouse, visible from Highway 440, is a collaboration between Lufa Farms; Laval-based Le Groupe Montoni Division Construction Inc., known for designing and constructing sustainable buildings; and the Dutch company Kubo Greenhouse Projects, a greenhouse designer and manufacturer.

Founder and president Mohamed Hage said Lufa uses its own technology to remotely monitor and manage crops at both greenhouse sites.

A proprietary software application helps the team quickly and accurately find, monitor, prevent and control diseases and other problems as they arise, Hage said, while an innovative venting system controls pests and temperature and optimizes sunlight for hydroponic crops.

The system also captures rainwater and recirculates irrigation water to avoid taxing the city’s water supply.

Lufa’s more than 2,000 subscribers order weekly on line year-round with produce from the two greenhouses and from more than 40 other Quebec organic growers and partners. They can pick it up at one of more than 130 drop-off points in and around Montreal.

“We like to say we bring the farmers market to you,” Hage said.

He said the new greenhouse puts high-yielding rooftop agriculture within the reach of any new building development in any city.

“We have learned how to cost-effectively grow food, distribute it, integrate it with local farming efforts and do it all in a sustainable and environmentally conscious way,” said Hage.