Vertical farming is the practice of producing food and medicine in vertically stacked layers, vertically inclined surfaces and/or integrated in other structures.
The modern ideas of vertical farming use indoor farming techniques and controlled-environment agriculture (CEA) technology, where many environmental factors can be controlled.
Hydroponic systems can be lit by LEDs that mimic sunlight. Software can ensure that all the plants get the same amount of light, water and nutrients. Proper management means that no herbicides or pesticides are required.
Taken from Wikipedia.com