Brian sent me information about Higher Ground Farm, which is putting down roots on the roof of the Design Center in South Boston.
“A roof farm is a type of green roof. A green roof is a system of layers that is laid over an existing roof. A green roof is beneficial to a building owner and the community because it protects the existing roof, doubling to tripling its life, thereby saving money and keeping materials out of the landfill.
“Green roofs also reduce a building’s energy costs by insulating in the winter and cooling the rooftop in the summer. Finally, green roofs temper the effects of two common urban environmental problems – combined sewer overflow and the urban heat island effect.
“A series of roof farms throughout the city will capitalize on the environmental benefits of green roofs while also increasing access to fresh, healthy food. Higher Ground Farm will operate several roof farms throughout the greater Boston area, utilizing previously unused space while providing additional rental revenue to a building owner.
“Roof agriculture has the potential to be a job-producing boost to the economy, and a completely environmentally sustainable business sector that can set Boston apart from other cities. Higher Ground Farm will utilize the resources of our top-notch universities to study roof agriculture, which will position Boston as a leader in the field. Finally, Higher Ground Farm will be a space where our community can reconnect to productive green space and learn about sustainable city planning.” More.
I also found a video interview about it that you will like, here.
Suzanne's Mom's Blog 
I love the idea! We all have to start thinking “outside the box” and remembering that we do have power to make a difference. Great post!
Thanks for commenting, My Daily Minefield. The one thing I haven’t been able to figure out is whether anyone can go there and walk around. I think the harvest will be sold at farmers markets, but I would like to have a walk there at lunch.