Green roofs are wonderful things, keeping buildings cool and reducing heat island effects. But you usually can't eat them. Now, rooftops around the world are being put to productive use as sources of food. Often they are tied to restaurants; Uncommon Ground in Chicago has a 2500 square foot rooftop garden. The executive chef tells the Chicago Sun-Times:
"We just used the peppers from the garden and stuffed them with chorizo. When things from the farm are ready, we'll incorporate it however we can. I come up once a day to see what's ripe and ready."
In Toronto, at the Fairmont Royal York, Twelve apprentice chefs tend the garden, weeding and watering, so that they can reap the benefits. Lemon balm, edible pansies, thyme, lavender, chives and different kinds of basil are just a few of the many herbs flourishing in the custom-built four poster wooden beds.
The Fairmont Royal York is not the only place raising bees on roofs; they do it in the Ginza in Tokyo. An NPO, Ginza Mitsubachi Project started beekeeping and has succeeded in keeping some 150 thousand bees with 260kg of honey gained each year. The honey is used in sweets by a famous confectionary shop.
Japan for Sustainability
Growing vegetables on a roof can be even more effective at reducing heat island effects than green roofs, as an experiment by NTT Developments showed.
They can get quite jazzy; Alexis Rochas designed this beautiful thing on a roof in LA, designed to be lightweight because of the existing building below. They are planning on harvesting tomatoes, herbs, greens, berries, wheat grass, even some monster cabbage.
Gotham Greens has installed is projected to produce 30 tons of fresh fruit, vegetables and herbs annually from its rooftop garden. "We are trying to demonstrate that sustainable, urban agriculture can be economically viable in the city," says their greenhouse director.
The next big trend will be the integration of greenhouses and hydroponic farms onto the roofs of new buildings, such as Bright Farm Systems' proposal for a social housing project in the Bronx. Soon, every building may have one of these.
Sun Works, the people who built the Science Barge, note that New York's 14,000 acres of unshaded rooftop could feed as many as 20 million people a year, more than the population of the city. Vertical farms might be pie in the sky, but horizontal ones on roofs make a lot of sense.