This article examines the role played by urban gardens during historical collapses in urban food supply lines and identifies the social processes required to protect two critical elements of urban food production during times of crisis—open green spaces and the collective memory of how to grow food. Advanced communication and transport technologies allow food sequestration from the farthest reaches of the planet, but have markedly increasing urban dependence on global food systems over the past 50 years. Simultaneously, such advances have eroded collective memory of food production, while suitable spaces for urban gardening have been lost. These factors combine to heighten the potential for food shortages when—as occurred in the 20th century—major economic, political or environmental crises sever supply lines to urban areas. This paper considers how to govern urban areas sustainably in order to ensure food security in times of crisis by: evincing the effectiveness of urban gardening during crises; showing how allotment gardens serve as conduits for transmitting collective social-ecological memories of food production; and, discussing roles and strategies of urban environmental movements for protecting urban green space. Urban gardening and urban social movements can build local ecological and social response capacity against major collapses in urban food supplies. Hence, they should be incorporated as central elements of sustainable urban development. Urban governance for resilience should be historically informed about major food crises and allow for redundant food production solutions as a response to uncertain futures.