This paper addresses the question under which conditions small-scale urban agriculture (UA) initiatives can accelerate a sustainability transition of the global food system. It develops the notion of a glocal garden, a large number of likeminded local initiatives with a global impact and forms of worldwide collaboration. Taking a transition perspective, the glocal garden, producing vegetables and fruits, is a niche that has to overcome barriers to compete with the dominant food regime. Since a sustainability transition restructures (policy) sectors, institutional domains including knowledge systems, the paper explores which innovations are needed for the glocal garden to succeed. It discusses the glocal garden as an environmental, a social, an economic and a global project. As an environmental project, the glocal garden will link sustainable production of food with renewable energy production. As a social project, it will be organized into a consumers' cooperative. As an economic project, it will strive for profit, increasing the yield in a sustainable manner. As a global project, it will enhance collaboration between local cooperatives in the North and the South, as well as with rural agriculture. Under these conditions, the glocal garden can develop into a power, able to resist a possible future food regime that splits societies, in terms of quality standards and food products, into haves and have-nots.