Urban agriculture (UA) has long been the subject of civic and scientific debate, since it provides cities with a diverse range of functions and services. UA is thought to have a positive effect on sustainable urban development in environmental, economic and social areas. Although most of the effects attributed to UA are positive, there are also critical aspects and concerns. For example, doubts have been raised about the quality of the products grown, considering the prevalence of air pollution and contaminated soils; and there are doubts about the contribution that urban agriculture makes to feeding urban populations, owing to the small quantities produced. Moreover, there are conflicts surrounding land use, especially in big cities; and in some cases, agricultural activities are undertaken in the city without the necessary building approvals. The concept of co-production and sharing as a (business) model is increasingly being applied with reference to urban gardens. This is particularly the case with volunteer-led community gardens, which are tremendously open to gardening enthusiasts and are renowned for the sharing of resources and space. Rather than seeking to make a profit, many of these initiatives operate under the principles of a non-profit or sharing economy. This chapter explores how UA can contribute to sustainable land management and co-production. To this end, background information is given on the (re-)emerging phenomenon of urban food production and on what motivates those involved to implement collaborative practices. The functions and services provided by UA as an element of sustainable land management are then explored using the three pillars of sustainability.