Vertical farming is the practice of producing food in vertically stacked layers, vertically inclined surfaces and or integrated in other structures. The modern idea of vertical farming uses Controlled-Environment Agriculture (CEA) technology, where all environmental factors can be controlled. These facilities utilize artificial control of light, environmental control (humidity, temperature, gases) and fustigation. Some vertical farms use techniques similar to greenhouses, where natural sunlight can be augmented with artificial lighting and metal reflectors.
Urban farming has taken a new direction and thus in search of farming space are scouring the cities. While there are other options like reclaiming unused land for cultivation, in Chicago, land comes at a high premium. Farmers here are eyeing spaces that they may not have to fight from developers: that is rooftops that are already green.