I'm not sure you'd call them vertical farms but Patric Blanc has done some amazing things to buildings in France, particularly Paris. Kind of an odd looking duck with his green striped hair, green nail polish and green shoes.
"There is enough in the world for everyones needs, but not enough for everyones greed"
*to my knowledge no vertical farm has ever been built so I'm not sure how someone can be an expert on something which doesn't exist....
It can be done. All you need is a REALLY steep hillside, plow it, seed it, and you're vertically farming. Play your cards right and you can cultivate both sides of the same acre!
OK, I'm just being silly. But it seems maybe unreasonably dogmatic to say that vertical farming is the ONLY way we can do something. It is an idea with plenty of good urban applications. and the vertical is an important axis, often overlooked. It's just not the only axis
Ideally, we make use of all four axes (height, width, depth, temporal) in our designs order to bring forth an optimal yield.