More for the rooftop.
Growing food where you live is one of the easiest ways to live greener. In a lot of cities people have been making a move to greenhouse farms on rooftops. There are some ambitious plans to incorporate gardening into large condo communities, and even multi-story greenhouses the size of city blocks. Gardening in the city just takes a different approach. I enjoyed these sites. http://triplehelixblog.com/2010/04/vertical-farming-the-farm-comes-to-town/ http://www.physorg.com/news/2011-04-huge-rooftop-greenhouse-montreal-local.html http://www.greenprophet.com/2009/03/knafo-klimor-israel-china/