Can you grow food underground?
Urban farmers are taking their crops under the city.
Busy Clapham High Street in London seems a strange place to be part of a farming revolution. However, unbeknownst to most passers-by, strange happenings are taking place right under their feet, or at least 33 metres below them. Utilising a former Second World War bomb shelter, Growing Underground grows micro greens and salad leaves such as pea shoots, wasabi mustard, and pink stem radish.
Built as part of a network stretching from Belsize Park to Clapham South, the original plan was to link them up after the war to form a high-speed underground line. Like many underground spaces they lay abandoned. Now in some of the world’s major cities a new breed of urban farmers using space-age techniques is taking them over.
Most of these farms use hydroponics, which grows the plants without soil in mineral-rich water. Although not exactly new− the earliest published research dates to 1627−hydroponics received a boost from NASA with its controlled ecological life-support system research into ways of supporting manned interplanetary expeditions.
The Growing Underground project plants the seeds on a bed of recycled carpet, which is then irrigated along with the use of LED lights as a sun substitute.
Co-founder Richard Ballard hit upon the idea after moving to London to embark on a film degree. “I was looking for film ideas and was intrigued with what was underground which led me to the tunnels. On top of that I was interested in the future of cities and food in general.”
Exotic holidays, immigration, and cookery shows have changed the way many people eat.
Exotic holidays, immigration, and cookery shows have changed the way many people eat − meaning a demand for year-round access to crops from the four corners of the globe. For Robert Liang, founder of New York’s Farm.One under Manhattan, this was the main inspiration. “I became fascinated by the range of interesting plants you could find in farmers markets around the world − but it’s difficult getting them out of season or in a location like New York. So, I looked for a way to grow year-round,” he explains.
Demand for exotic ingredients increases food miles and contributes to pollution and global warming. By growing in a population centre this reduces to near zero. La Caverne, which repurposed a disused underground car park in Paris, uses bicycles for delivery, and New York’s Farm.One uses a similar approach along with the subway.
Meanwhile in Stockholm, Plantagon, which in June opened its first underground farm three storeys below the DN-Skrapan building, mainly grows basil, thyme, and coriander.
“We will produce 20 tonnes of herbs a year when fully operational. Usually they would be brought in from Spain, Egypt, and Kenya,” says Mia Kleregård, Plantagon’s deputy chief executive officer.
An added advantage is that the product is much fresher; often picked on the same day as consumption. “There’s a huge difference between a product shipped from hundreds of miles away, and something picked that morning down the street,” says Liang of New York’s Farm.One.
A controlled underground environment allows replication of optimum growing conditions and makes growth no longer weather dependent. “The plants get the perfect conditions, due to light, nutrition, and water,” notes Kleregård.
Temperatures underground are far more constant throughout the year with the tunnel in Clapham being around a steady 15 degrees Celsius without heating. Such a controlled environment means there is no need for the use of pesticides. However, due to the lack of soil under EU rules, crops grown by hydroponics cannot be classified as organic.
Without sunlight crops are dependent on LED lights for growth. Waste heat from these can be a problem. The Plantagon system uses this to heat the office building during winter allowing reuse of up to 70 per cent of the energy; Growing Underground uses the heat to bring up the temperature to the optimum 20 to 25 degrees Celsius for the crops. In Paris the problem is not so big. “LED farming represents less than 5 per cent of our activity. Chicory grows in complete darkness and mushrooms require very little lighting,” says Théo Champagnat, La Caverne co-founder.
Plantagon has plans for ten farms around Stockholm and is in talks for projects around the world. Growing Underground currently use only around 500 square metres of the 3,000 square metres of tunnel available. Similarly, La Caverne will expand from their current 2,000 square metres to occupy the full 3,500 square metres of their car park. Farm.One was built from the start to be replicable.
“This is definitely one of the components of the future of farming. It is, though, dependent on cheap and ultimately renewable energy. The LEDs we’re using at the moment are still in their infancy but in the future people are working on light recipes to really get the best out of a certain crop,” says Ballard.
Text Mark Andrews
Illustration Siiri Väisänen