Walking into the Felix Thomas REWE supermarket in Lankwitz, Berlin, customers are immediately presented with a choice of greens: romaine, rocket, iceberg. But last month, a new option joined the selection: Lankwitz loose-leaf lettuce. A combination of head lettuce, romaine lettuce, Lollo Rosso, and dark green easy leaf lettuce, its yellow packaging makes it stand out in a row of green.
But it’s not just the flashy packaging that makes it distinct. Unlike its neighbouring lettuces, which come from regional farms or all the way from Italy, these greens were grown just a few metres away – or rather, a few metres up. Rooftop farms are nothing new: in cities such as Paris, Hong Kong, Copenhagen and New York, similar farms supply food to adjacent food retailers or even restaurants.
This model has the potential to reduce greenhouse gas emissions from transportation (and its associated costs), minimise the urban heat effect, make use of dead space and perhaps even improve the relationship between buyers and their food. Germany is also no stranger to rooftop farms. In 2021, REWE and ECF – a Berlin-based agricultural technology company – opened their first green farming market on top of a store in Wiesbaden-Erbenheim, selling basil below.
But at 2,760 sq metres, the Lankwitz REWE is now Germany’s largest rooftop farm. REWE provides the space, location, and distribution channels to sell, and ECF designed and manages the greenhouse. The Lankwitz lettuce has become a selling point of sorts: store manager Felix Thomas says one customer travelled more than 50km just to get their hands on a bag.
And the integration of the farm into REWE’s market and corresponding supply chain is novel, says ECF CEO and founder Nicolas Leschke. The supermarket was clearly designed with the farm in mind: skylights throughout the store offer a window into what’s growing above. The greenhouse is heated through the waste heat of cooling aggregates downstairs, and rainwater is the primary source of water for the greenhouse and plant production.
Some of the greenhouse is also powered by sustainable energy – primarily solar. The operation is meant to be year-round. The farm makes use of hydroponic technologies: the lettuce varieties are grown with very little soil.
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