Own‐grown fruit and vegetable production in urban areas is increasingly assumed to increase food security, however, the evidence‐base to support this assumption is lacking. By integrating remotely sensed Geographic Information System data, fieldwork, and a citizen science project (MYHarvest) we will estimate the current levels of UK own‐grown fruit and vegetable production and how this could be increased if more urban land was made available for own‐growing. This will provide the first comprehensive UK dataset on own‐grown production for use by research scientists, policy‐makers, and the public, and will highlight the importance of urban horticulture to local and national food security.