Garden Culture Tours World’s First Commercial Rooftop Greenhouse

It’s not every day you get to tour a farm that has revolutionized the way food is grown and how people eat. Lufa Farms built the world’s first commercial rooftop greenhouse on an industrial building in Montreal, Canada. Depending strictly on hydroponics, crops are grown year-round and produce high-yields, feeding the city in an incredibly healthy and sustainable way.

Garden Culture Magazine got to see how it’s done.


Open the door to the greenhouse at Lufa Farms and you’re greeted by a sea of green; row upon row of sprawling cucumber vines, lush pepper plants, and what appears to be an endless supply of fresh herbs and microgreens. The scents of truly fresh food hit you almost right away; sweet, peppery and even grassy aromatic waves come and go. The time and effort put into what is grown here are humbling; so is the amazing technology used and the fact that unlike most commercial greenhouses, we’re three stories high on a rooftop overlooking the city of Montreal.

The Dream: Fixing A Broken System

Lufa Farms lives and dies by the rule of being fresh, local and responsible, and the passion and dedication to that motto are evident as you walk through the greenhouse. It wasn’t so long ago that all of this was a dream; co-founders Mohamed Hage and Lauren Rathmell wanted to fix a broken food system by reconnecting city-dwellers with what they put into their bodies. The idea was to feed cities with food grown in their own backyards, or in this case, on their very own rooftops so as not to put any more pressure on agricultural land outside of the city.

In 2009, Hage and Rathmell started searching Google Maps for available rooftop space in the city that had just the right amount of sun. They narrowed the list down to 10 roofs, and all but one building owner said ‘no’ to their vision of building a greenhouse closer to the sky. Two years later the first planting began. Today, the company has expanded to three hydroponic rooftop greenhouses across Montreal, providing 138,000 sq ft of growing space for everything from cucumbers, tomatoes, and eggplants, to peppers, fresh herbs, lettuce, and microgreens. With each greenhouse built, Lufa becomes more sustainable and efficient in their practices. For example, its most recent greenhouse is incredibly high-tech; from seed to harvest, plants automatically roll through the greenhouse to various zones ideal for their current growing stages. How’s that for sophistication?

How It Works  


The concept behind Lufa is simple: people customize their very own food baskets online, ordering everything from fresh fruits and vegetables to locally-crafted bread, pasta, cheeses and even chocolates. All of the 230 partners are chosen for the fact that they too practice sustainability. Some are organic, but all of them meet Lufa’s high-standard of being environmentally responsible.

When Lufa Farms first started in 2009, it distributed 300 baskets a week. Today, it delivers close to 13,000 to customers across the province of Quebec. Everything in the baskets is harvested to order, meaning a few short hours after the order is placed, the particular basket’s contents are picked or baked, packaged in compostable bags, and delivered to one of 450 pick-up points. Lufa also has a fleet of electric cars to facilitate home deliveries.  

The rise in Lufa’s popularity was almost inevitable, driven by not only the quality and freshness of its food but by the five principles that guide its way of farming:

1. Using No New Land

Lufa Farms repurposes what already exists and to relieve pressure on the world’s soil, never develops new land. Rooftops are lost space, so building greenhouses there makes sense and also helps them farm closer to city-dwellers.

2. Beneficial Bugs

No pesticides, herbicides or fungicides are ever used at Lufa Farms. In fact, beneficial insects are introduced to the greenhouse to control pests the natural way. Non-invasive ladybug species and parasitic wasps eat the aphids on the crops; bumblebees have been brought in to pollinate the plants.

3. Saving Energy

The beauty of growing in a rooftop greenhouse is that heat comes fairly cheap from the sunlight and the building below. The benefits are mutual; Lufa says the building owners have also reported saving 30% in energy costs every year.

The LED lights used for seedlings and microgreens don’t use very much energy, and the HPS lighting used for other crops also generate a good amount of heat. When we took our tour, an “energy curtain” had been deployed by a software that constantly examines the heat and light levels in the greenhouse. It acts as a blanket, providing perfect conditions for the food growing in Montreal’s temperamental climate. Air conditioning is never used to cool the crops when it gets too hot; instead, a huge cardboard panel mounted on the wall has cold water running through it, and ventilators on the other side of the room pull the resulting cool air through the greenhouse.     


4. Saving Water

All of the water used inside the greenhouse is recirculated through a closed-loop system and delivered to the crops. Water that isn’t used by the plants runs down the sloped tables below them, finding its way into a gutter-like system which brings it back to a holding tank. Being on a roof, the greenhouse also collects irrigation water which is fed to the plants after nutrient solutions are added.

5. Reducing Waste

One-third of the world’s food goes to waste, and Lufa Farms does its part by harvesting only what has been ordered by its customers and delivering it at the peak of its freshness. Even though the greenhouses are completely hydroponic, any green waste is composted and sold in the online marketplace.

How It’s Grown

As already mentioned, Lufa Farms depends strictly on hydroponics to grow all of its produce. It uses two systems: NFT and grow bags, depending on the various needs of the crop. Coconut fiber is the substrate of choice, and with little choice, the fertilizers used are synthetic.

The HPS lights are more commonly-used in the areas of the greenhouse where the cucumbers are grown, for example, which aren’t native to Canada and demand a lot of light and heat. The LED’s are used for the herbs and microgreens so as not to burn their delicate leaves while providing their lighting needs. The day’s natural periods of light and dark are always obeyed, meaning the grow lights are never used continuously overnight.

Growing hydroponically means Lufa Farms doesn’t use soil, and therefore can’t qualify for organic certification. But it carefully weighed the pros and cons of each before embarking on this amazing venture. Hydroponics was the natural choice because at the core of Lufa’s values is the desire to grow where most of the population lives while also reducing pressure on our soil. Contrary to conventional farming, the hydroponic systems used in Lufa’s greenhouses recycle all of the water and nutrients used, resulting in very efficient practices.  

A True Inspiration

The love, passion and hard work behind the food grown at Lufa Farms are clear, as is the connection it has made from farm to table. Lufa is a leader in the world when it comes to growing food for its taste and nutritional value, rather than for its longevity, durability, and potential for uniformity. What started out as a dream to change the way we eat has finally become a reality. And I’m inspired.   

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Catherine Sherriffs

Editor at Garden Culture Magazine

Catherine is a Canadian award-winning journalist who worked as a reporter and news anchor in Montreal’s radio and television scene for 10 years. A graduate of Concordia University, she left the hustle and bustle of the business after starting a family. Now, she’s the editor and a writer for Garden Culture Magazine while also enjoying being a mom to her three young kids. Her interests include great food, gardening, fitness, animals, and anything outdoors.