In Count Zero by William Gibson there is a description of the future "Boston-Atlanta Metropolitan Area" where the projects have become at least partly self-sustaining:
"... the Projects rose beyond the opposite shore, vast rectilinear structures softened
by a random overlay of retrofitted greenhouse balconies, catfish tanks, solar heating systems, and the ubiquitous chicken-wire dishes...."
"Finally, they were approaching a wall of some kind. Bobby looked back. Shallow pools on the muddy concrete floor caught and reflected the limbs of the dwarf trees, the bare pale roots straggling down into makeshift tanks of hydroponic fluid.
'Then they pump that into shrimp tanks, and grow a lot of shrimp. Shrimp grow real fast in warm water. Then they pump it through pipes in the concrete, up here, to keep this place warm.'
That's what this level was for, to grow `ponic amaranth, lettuce, things like that. Then they pump it out into the catfish tanks, and algae eat the shrimp shit. Catfish eat the algae, and it all goes around again. Or anyway, that was the idea. Chances are they didn't figure anybody'd go up on the roof and kick those Darrieus rotors over to make room for a mosque, and they didn't figure a lot of other changes either.
'So we wound up with this space. But you can still get you some damned good shrimp in the Projects. . . . Catfish, too.'"
I imagine a future where the topiaried ornamentals now growing on these roof terraces will make way for fresh fruits and vegetables. Even urbanites need to be connected to the world.
Now, I'm making this sort of thing happen in SE Portland for a "living" as the more diminutive half of the Sellwood Garden Club.