The EAT-Lancet Commission recommends increasing the consumption of nut trees worldwide as part of a sustainable diet. Integrating more nut tree species in urban gardening initiatives could provide members access to locally grown nuts and provide ecosystem services to urban landscapes. This study investigated the reported presence and diversity of nut tree species in urban community gardens, as well as the motivations and challenges for adopting and expanding those trees. Based on an online survey with 111 responding projects from the urban community gardening network in Germany as our case study, we found that nut tree species exist in almost half of all responding projects surveyed, albeit in a few numbers of individual trees and producing low yields. Projects are motivated by the provisioning, regulating, and cultural ecosystem services they provide, such as the nutritional value of nuts, the provision of food for animals, and the potential for education of members about agroforestry and nut use. Yet projects are hindered by limited space, local laws and regulations, and the interaction of nut trees with other species in the garden. Although only 50% of projects plan to incorporate more nut tree species in the future, most recognize the importance of nuts as part of a healthy diet. Governmental leadership is necessary to secure long-term contracts for urban gardens, so that more nut trees can be planted, and city residents can exploit the benefits of the ecosystem services they provide.