National Public Radio: From vacant lots to vertical "pinkhouses," urban farmers are scouring cities for spaces to grow food. But their options vary widely from place to place.
While farmers in post-industrial cities like Detroit and Cleveland are claiming unused land for cultivation, in New York and Chicago land comes at high premium. That's why farmers there are increasingly eyeing spaces that they might not have to wrestle from developers: rooftops that are already green.
The green roof movement has slowly been...