Vertical Farm
GROWING UNDERGROUND
From offering shelter to cultivating food
Adventures in vertical agriculture
I entered an aging white building from an alley off the high street in Clapham to a chamber with a wide spiral staircase going into a black hole. My guide asked if I wanted to walk down the 108 feet (33m) but instead I opted to take the antique (yet well-oiled) industrial elevator. At the bottom, I was surprised to feel the humidity on my face, and both hear and feel the rumble of an arriving tube car in the distance. In front of me was a series of doors and tunnels leading to various wet and dimly-lit rooms full of workers. After suiting up in galoshes, a lab coat and hairnet, I was led into the main event--a brightly-lit place teeming with shelves of plants and LED lights. This is Growing Underground, a vertical farm ingeniously built into an old air raid shelter below the Clapham Common Tube station in London.
Growing Underground is a hydroponic vertical farm—using 70% less water than your typical farming operation. They utilize a closed-loop ebb and flow system where water with nutrients floods the beds of sprouts a few times a day and then is recycled through a reservoir and reused. The plants float in a substrate made from recycled wool carpeting. Lights sit above the plants and are turned on and off to simulate daylight and night time. In the UK, power costs less at night, so the lights are off during the day and turned on in the evenings. In addition to the water and lights, the grow room also has a system of fans to keep air circulated. Given their unique insulated location,108 feet underground, the tunnels naturally provide a consistent microclimate year round. The whole grow process takes between 10-20 days from seeding to harvest, based on the plant's specific growth cycle.

Growing Underground has been supplying food to the market since 2016, and they currently grow over 16 varieties of microgreens ranging from more common sprouts like sunflower to more exotic varieties like wasabi and mustard. While the proof of concept was with lettuce, the co-founders decided to pivot to growing microgreens because they take less time to grow and are a desirable commodity for local chefs and home chefs too. They sell directly to Whole Foods, M&S, and a handful of other London-based grocers and restaurants. The just-picked greens are marketed, for some stores, as a 'micro-salad' offering a delicious (I can attest) spin on your typical salad. Although small, these plants pack your mouth with a surprising, flavorful bundle of taste (and high nutrient content too.)
Just one exposure to harmful bacteria could cause the entire industry to look bad.
Safety and regulations
Food safety is paramount across the vertical farming industry, and Growing Underground is no exception. They take hygiene and cleanliness at the farm very seriously. Anyone entering the farm must remove jewelry, wear a sterile suit and boots, and cover their hair. I even had to answer a questionnaire before being admitted to the farm, which inquired about things like current illnesses or exposure to risky settings (like poultry farms) to ensure no one visiting contaminates the crops. Visitors aside, they run a tight ship when it comes to cleanliness, setting aside part of every day to clean the tunnels and processing areas.
The EU does not categorize plants grown in soilless mediums, like hydroponics, as 'organic.' However, Growing Underground does not need to utilize pesticides, fungicides, or herbicides because bugs and disease are not common given the controlled environment, quick plant life cycles, and their emphasis on cleanliness. At the moment, they are partnered with Nottingham Trent University to find ways to grow even greener, without the use of chemical nutrients for feeding the plants or water purification.

Unlike a lot of other farms, they own the supply chain from sprout to grocery store, processing all greens onsite and delivering them to customers. This process allows for the highest level of traceability and accountability. In a new concept like vertical farming, just one exposure to harmful bacteria like e.coli could taint consumers' views on the safety of the entire industry. Hence it is essential that vertical farms go the extra mile to ensure their product is safe.
Trays of fresh micro greens on their way to the consumer
Innovations and challenges
Innovation is key to the survival of any vertical farm because there are not a ton of agreed-upon best practices, instruction manuals, or even groups sharing growing tips. Growing Underground is continually testing out things, like new substrates or plant varieties, to be more sustainable, cost-efficient, and environmentally-friendly.

Vertical farms can cultivate regardless of the season; however, Growing Underground noted that buying habits from consumers and restaurants reflect seasonal choices with more demand for microgreens in the spring and summer. Seasonality may be one challenge all vertical farms will need to consider especially with slow food and Ayurveda globally spreading.

Despite all of the challenges and risks inherent to a new industry, Growing Underground is the only vertical farm I could find in London that is growing food, shipping their food to grocery stores and restaurants, and planning to expand their farm into more tunnels soon. In a cosmopolitan city prioritizing health (if juice bars on every corner and the abundance of grass-fed beef on menus is any indication) Growing Underground is well-suited to be a key player in the future food industry.
Subscribe to learn more and stay in the loop!