Watercress seedlings grow on AeroCloth, a growing material, in a vertical farming bed beneath light emitting diode (or "LED") lamps and using a patented growing algorithm of controlled light, nutrients and temperatures for growing a variety of baby greens at an AeroFarms Inc. indoor vertical farming facility in a former indoor paintball arena in Newark, New Jersey, June 24, 2016. Picture taken June 24, 2016. REUTERS/Mike Segar

Watercress seedlings grow on AeroCloth growing material in a vertical farming bed beneath light emitting diode (or "LED") lamps and using a patented growing algorithm of controlled light, nutrients and temperatures for growing a variety of baby greens at an AeroFarms Inc. indoor vertical farming facility in a former indoor paintball arena in Newark, New Jersey, June 24, 2016. Picture taken June 24, 2016. REUTERS/Mike Segar

Employees toss freshly harvested watercress that was grown in vertical farming beds beneath light emitting diode (or "LED") lamps and using a patented growing algorithm of controlled light, nutrients and temperatures for growing a variety of baby greens at an AeroFarms Inc. indoor vertical farming facility in a former indoor paintball arena in Newark, New Jersey, June 24, 2016. Picture taken June 24. REUTERS/Mike Segar

Watercress seedling grow on AeroCloth growing material in a vertical farming bed beneath light emitting diode (or "LED") lamps and using a patented growing algorithm of controlled light, nutrients and temperatures for growing a variety of baby greens at an AeroFarms Inc. indoor vertical farming facility in a former indoor paintball arena in Newark, New Jersey, June 24, 2016. Picture taken June 24. REUTERS/Mike Segar