Vertical farms grow crops indoors in stacked layers, using artificial lighting and carefully controlled temperature and humidity. Plants are often grown without soil, with their roots in water containing nutrients. Because conditions are controlled, crops can be produced all year round, regardless of the weather outside, and pesticides are rarely needed. Supporters argue that vertical farms can be built close to cities, reducing the distance food must travel. They also use far less water than traditional fields, since water can be collected and reused. The biggest challenge is energy. Replacing sunlight with electric lights is expensive, and several vertical farming companies have gone out of business when electricity prices rose. For this reason, most vertical farms today concentrate on leafy vegetables and herbs, which grow quickly and can be sold at relatively high prices. Staple crops such as wheat and rice require large amounts of light and space in relation to their value, so growing them indoors is not currently economical. The future of the industry may therefore depend on cheaper renewable electricity and more efficient lighting.

Vertical farms generally use more water than traditional fields.