> Research in the 1970s by John Jeavons and the Ecology Action Organization found that 4000 square feet (about 370 square metres) of growing space was enough land to sustain one person on a vegetarian diet for a year, with about another 4000 square feet (370 square meters) for access paths and storage – so that’s a plot around 80 feet x 100 feet (24m x 30m).

That’s about a fifth of an acre, and other caveats apply like climate and the amount of labor during the growing season. If vertical farming works, and can also reduce the labor required (I have no idea if that’s one of its goals), it starts to look more plausible as something that could take off. Still won’t fit on a rooftop though, and as Jayne would say, “I smell a lotta ‘if’ coming off that plan.”

https://www.growveg.com/guides/growing-enough-food-to-feed-a...