In the last few years living roofs, have been sprouting up all across the United States. Now architects and farmers are taking the concept one step further, by turning them into urban farms - And what better place to start, then the concrete jungle known as New York!

While small personal rooftop farms have been around, two New York based companies; Brooklyn Grange and Gotham Greens are now trying to turn it into profitable commercial businesses.

Brooklyn Grange's, first project is a 40,000sq.ft. farm set atop a six-story commercial building in Queens, New York. Last week, hundreds of volunteers got together to lay the soil - except in this case it isn't really soil, but about a million pounds of Rooflight - an engineered mix that provides all the nutrients required by plants sans the soil.

The project is being led by Ben Flanner, a young farmer, from Wisconsin, who has successfully tested the idea, with a smaller 6,000sq. ft. roof farm in Greenpoint, Brooklyn. He hopes to sell his produce, which depending on the time of year, will include tomatoes, carrots, kale, broccoli, squash and cabbage, to the local people and restaurants in the area. To read more about Brooklyn Grange, check out their website brooklyngrangefarm.com.

Gotham Green, the brainchild of three young New York-based entrepreneurs, is also testing the same concept, except their approach is entirely 'green'.

Their first project, scheduled to open later this year, is powered by solar panels and instead of the traditional method of farming, they plan to use Hydroponics, a technique where plants grow directly from nutrient-filled water. Not only does this increase the crop yield, but also, requires less water than traditional farming.

For irrigation, the team will use rainwater collected in a large cistern built on the edge of the rooftop. Instead of harmful pesticides, the company will use insects like ladybugs and wasps to protect the crops. Once ready, the produce will be shipped to customers on bicycles or renewable-energy powered vans, depending on the distance and/or volume.

Gotham Greens believes that it's 16,000sq.ft. lot will yield about 40 tons of vegetables, 70% of which will be sold to Whole Foods. If the project is successful, the company plans to construct several similar farms all across New York City. To read more about the company and its future plans check out their website gothamgreens.com.

sources: budez.com,emoiz.com,brooklynrangefarm.com,gothamgreens.com