It sounds like Havana has become a glorious example of how effective organic urban farming can be.
"Twenty years ago, Cuban agriculture looked very different. Between 1960 and 1989, a national policy of intensive specialised agriculture radically transformed Cuban farming into high-input mono-culture in which tobacco, sugar, and other cash crops were grown on large state farms. . . But after the collapse of the Soviet Union, the oil supply rapidly dried up, and, almost overnight, Cuba faced a major food crisis."
"Havana [now] has almost 200 urban allotments - known as organiponicos - providing four million tonnes of vegetables every year - helping the country to become 90% self-sufficient in fruit and vegetables."
"At the time of the oil shock, average calorie consumption in Cuba dropped by a third to dangerously low levels. Since then they have bounced back and Cubans eat just a little less than people in the UK."