In the past 5 years, New York City has begun to see a different kind of green roof take root on the tops of expansive industrial buildings in the outer boroughs. In the face of increasing demand for local, organic, and sustainable food, several rooftop farms have popped up in Brooklyn, Queens, and the Bronx to provide high quality greens, vegetables, and honey to city residents. These farms offer many of the same environmental advantages as standard extensive green roofs with one major added benefit: delicious, fresh, and local produce.
Two years ago, on the roof of an oddly shaped industrial building at 37-18 Northern Boulevard in Long Island City, Queens, a promising young start-up called Brooklyn Grange installed their first rooftop farm. At its inception, the goal was to find suitable rooftop space to farm in Brooklyn, but when the building in LIC became available, Ben Flanner, the company’s President, jumped at the opportunity.
After adding a second roof on a building near the Brooklyn Navy Yard this spring, Brooklyn Grange now has more than 100,000 square feet of farming space in the city. Each year, the roofs produce tens of thousands of pounds of tomatoes, peppers, herbs, greens, and many other fruits and vegetables. The bounty ends up at local farmer’s markets, city restaurants, and local supermarkets.
The installation was quite different from your standard green roof. On top of the typical root barrier, and drainage layer, Brooklyn Grange added a whopping 1.2 million pounds of specially prepared soil to the roof, to provide 7.5 inches of growing depth.
And don’t expect normal green roof maintenance to suffice when it comes to taking care of rooftop farms. In comparison with the relative ease of caring for sedum green roofs, rooftop farming is a full time job. Brooklyn Grange continuously farms its roofs for 9 months out of the year. During the 3 winter months, clover, rye, and vetch are grown as cover crops to retain soil. All in all, Brooklyn Grange’s employees and volunteers work year round to ensure the farms remain viable and productive.
Farming on a roof provides for some unique advantages over conventional farms. Rooftop farms benefit from being isolated from most pests, especially mice, rats, and rabbits. In addition, crops enjoy plenty of sunshine without obstruction. A rooftop setting does present many challenges though, including wind, space and depth constraints, and building load concerns.
Rooftop farming provides cities with yet another option to control stormwater runoff, reduce energy use and the urban heat island effect, and increase biodiversity. Urban farming has the added benefit of providing extremely local, sustainable produce. Couple these benefits with the potential for bringing healthy food into New York City’s most food stressed neighborhoods, and you can expect to see many more rooftop farms in the future.
-Ryan Withall (firstname.lastname@example.org)