Tel Aviv’s rooftop farm grows fresh food for thousands
The rooftop farm produces 10,000 heads of lettuce per month year-round, and grows 17 different varieties of greens and herbs; there is even a banana tree. The farm uses a variety of hydroponics systems – some vertical, some horizontal – that grow food two times faster than in soil. The system does not require regular cleaning, since the sun does not access the water beneath the plastic covers that hold the plants, and the constant flow of oxygen prevents rot. The vegetables are grown without pesticides.
http://www.treehugger.com/green-food/tel-avivs-rooftop-farm-grows-vegetables-thousands-people.html