The growing popularity of urban horticulture is being driven by growth in urban agriculture in general. This is particularly prominent in urban inner cities areas sometimes characterized as “food deserts.” The motives for the urban agriculture movement in these areas are multifaceted. Critics who dismiss the movement for its lack of economic potential fail to understand that its social and cultural contributions are perhaps even more important than its significant contributions to intercity employment and food security. The urban agriculture movement is not new. Prior to the industrialization of agriculture, people in cities met many of their food needs from urban gardens and truck farms in peri-urban areas. The Garden City Movement of the late 1800s was a response to concerns for urban food insecurity that had resulted from reliance on the market-driven, industrial food system. Industrialization of agriculture, although successful in increasing production, had failed to provide domestic food security. Urban agricultural movements of the past have blossomed during times of food scarcity and income insecurity, particularly during times of war and economic recession. The current urban agriculture movement is different, in which it is continuing during times of agricultural abundance and economic sufficiency. Urban horticulture is more adaptable to urban areas than livestock or grain production. Thus, the current movement is commonly identified as an urban horticulture movement. The potential importance of the urban horticulture movement becomes readily apparent when it is viewed as part of the much larger sustainable agriculture or agri-food movement. Agricultural sustainability is not simply a matter of economic efficiency but also requires ecological, social, and economic integrity. Social and environmental benefits, which are prominent attributes of urban horticulture, are critical to agri-food sustainability. Lacking economic incentives, government policies will be essential to ensure the social and ecological benefits essential for agri-food sustainability. Past government policies supporting industrial agriculture have been justified as essential for food security, but have failed. The first condition of agricultural sustainability is to meet the basic food needs of the present—food security. The second requisite is to do so without diminishing opportunity for future generations. Government policies of the future should logically be redirected to ensure agri-food sustainability, including sustainable urban horticulture. Perhaps most important, the urban agriculture movement is empowering people in inner cities to take control of their own destinies. The urban agriculture movement exemplifies the ethics of social responsibility essential for agricultural sustainability.