Deep beneath the streets of London, in a complex of bomb shelters left abandoned since World War II, something is growing. Thousands of green sprouts burst from their hydroponic trays, stretching toward glowing pink lights that line the arched ceilings. These plants, along with tens of thousands of other salad crops, are being grown from seed without soil or sunlight, in tunnels transformed into a high-tech commercial farm.
The farm is known as Growing Underground (GU), and it’s located 108 feet below the main street in Clapham, a south London suburb. Every year, in 6,000 square feet of old bomb shelter, more than 100 tons of pea shoots, garlic chives, cilantro, broccoli, wasabi mustard, arugula, fennel, red mustard, pink stem radishes, watercress, sunflower shoots, and salad leaves are sown, grown, and prepared for dispatch.
In short time the indoor farm grows a compact, intensely flavored product in conditions that not only suit the plant but meet the needs of the growers, too. “The cycle for growing coriander has gone from 21 to 14 days,” explains Riley Anderson, the site’s team leader. “Some plants can be harvested after just six days in the growing tunnel, which beats anything a farm aboveground can achieve consistently through the year.” They toyed with duller tones than the vivid pink that now illuminates the growing tunnel, but found that the reduction in visibility meant having to lift each plant tray out off of its bench to do quality checks. It slowed the process and didn’t enhance the crop.
“We wanted to source the lowest energy consuming lighting system we could find,” explains Ballard. “The LEDs do not use the same amount of energy nor do they create the high direct heat that conventional (high-pressure sodium) lights do, which means we’re able to grow the plants in shelves closer together.”
The power comes from Good Energy, which only uses renewable sources. “As it’s a closed-loop system of farming, anything that’s added—nutrients or fertilizers—stays within the circuit,” says Ballard. The only farm waste—the substrate recycled carpet left over from harvesting the herbs—is sent to SELCHP, a waste-to-energy converter in southeast London. “Zero carbon output has been the Key Performance Indicator we chose to work to from the very start because any business starting today needs to think about its impact on the environment,” says Ballard.