Shaping the Future of NYC

While I am aware that we are in constant need of low income housing and job opportunities, I really would like to focus on bringing some exposure to natural beauty into New Yorker’s every day lives. What I would like to see are some low-cost–maintenance public gardens, where New Yorkers can rent a plot and care for and grow their own vegetables and flowers.
There is one I know of already in Flushing near the Booth Memorial Hospital, called the Kissena Corrider Park. ( http://www.treebranch.com/BQGG_pdf/kissena_cunningham.pdf ) I think it would be great, if possible, to find some small plots of space outdoors in urban residential areas, or even to put greenhouses on the roofs of buildings that the public could access, so that New Yorkers can de-stress and discover their green thumbs.