Urban planners, architects, politicians and residents all agree that cities need more greenery. There are numerous approaches to this. Green façades, roof gardens and the targeted redevelopment of industrial wastelands, to which New York owes its Highline so popular with locals and tourists alike. But what if it’s not just about creating pockets of greenery amid pavement, steel and glass? Urban farming is going a step further, for it aims to bring food production into the city.