In the words of Wikipedia "A roof garden is any garden on the roof of a building. Besides the decorative benefit, roof plantings may provide food, temperature control, hydrological benefits, architectural enhancement, habitats or corridors for wildlife, and recreational opportunities...Roof gardens are found most often in urban environments. The plants reduce overall temperatures of the building which in turn reduces energy consumption. "The primary cause of heat build-up in cities is insolation, the absorption of solar radiation by roads and buildings in the city and the storage of this heat in the building material and its subsequent re-radiation"
Hereunder some Roof Gardening links:
http://www.urbanroofgardens.com/
http://www.hydrotechusa.com/garden-roof.htm
http://www.carlisleroofgardens.com/
http://www.alivestructures.com/
*photos from urbanroofgardens.com
