Growing Underground, London’s carbon-neutral farm, expects to supply restaurants with truly green produce.

One hundred feet below ground in south London might not seem like the obvious pick for the location of a working farm. But that’s just what’s happening beneath the city’s Northern subway line, as entrepreneurs Richard Ballard and Steven Dring realize their vision of a carbon-neutral urban farm—located in an extensive network of tunnels once used to shelter London residents during World War II air raids.

The business partners, whose idea for an underground plot took root across many evenings in the local pub, share a passion to craft a carbon-free urban environment, one that does not emit carbon dioxide into the atmosphere, while also connecting city dwellers with how food is grown. Teaming up with the pair is Michel Roux Jr., the two-star Michelin chef behind London-based Le Gavroche, who thought the two men were crazy when he first heard of the project. Roux changed his mind after touring the tunnels, tasting crops grown in testing mode, and declaring the samples “delicious.” Now, he's embraced the concept and is a director helping to decide produce selection.

For the past 18 months, horticulture expert Chris Nelson has been testing which crops to plant, concentrating on micro-shoots and herbs. Full-scale construction of the farm, named Growing Underground, began in March—following a flurry of fundraising efforts that included crowdfunding as well as bringing in larger investment sources from the likes of the United Arab Emirates.

The carbon-neutral farm, situated on a mere 2.5 acres, uses advanced low-energy LED bulbs “with a perfectly balanced light spectrum to grow crops hydroponically,” says Dring. The produce is grown on specially constructed three-layered platforms.

“Below ground is a great environment—it’s the same temperature all year, and it’s not affected by weather,” says Dring. Temperatures are kept at a steady 60 degrees Fahrenheit. Special filters keep the air in the tunnels free of pests, eliminating the need for pesticides. Water comes through the tunnel system’s sump room, explains Dring, “We make sure the water is clean [filtering out all impurities] and then feed the water right to the crops.”

Produce is expected to hit restaurants and shops by late summer. Initial crops were chosen for their “intense flavors,” notes Dring, and include red amaranth, broccoli, mizuna, garlic chives, mustard leaf, radish, coriander, and Thai basil. Edible flowers and miniature vegetables are also in the works. Stage two crops will include heritage tomato varieties and mushrooms.

Crops will also change based on feedback from chefs and restaurants. For example, red sorrel will be part of the mix since a local chef told Dring: “It’s hard to get a good crop of sorrel; it’s so delicate. It’s hit or miss in the market.”

Feature, NextGen Casual