Use of modern agroforestry systems in urban areas is on the rise. Alternative uses for public space through urban gardening projects have existed in North America since at least the 1970s and 1990s in Europe. More recently, some projects have started including shrubs and trees to provide food, environmental services, personal recreation, and bioenergy. To date there has been little research on the factors that enhance or inhibit the diffusion of such projects. 62 urban agroforestry projects in USA/Canada and 24 projects in Germany were found through a systematic online search. Whereas the first projects in North America started in 1998 and reached a peak in 2011 followed by a slump in numbers after 2015, the trend started considerably later in Germany around 2005. Similarly the peak was around 2011/12 in Germany; however, since that time new projects have emerged every year. Based on Roger’s theory of the Diffusion of Innovation, which divides trends according to distinct phases – knowledge – persuasion – decision, and confirmation, 12 criteria were developed to evaluate and rank the projects according to their phase. To some degree, this ranking reflects the stage of development and possible sources for userexperience. Mapping of project diffusion over time indicates that they largely started in major cities with universities, primarily on USA’s West Coast. Detailed analysis of six selected projects and expert interviews provided rich insights into their development, as well as obstacles and needs of stakeholders. Important for success is the role of experts especially during the establishment phase. Not solely experts for trees and plants, but also with civic management expertise. A number of legal constraints are experienced, and prejudices and initial distrust by locals was common throughout the course of project implementation. Newly established urban agroforestry projects need broad community support. Networking between projects is also essential for lasting success.     «

Use of modern agroforestry systems in urban areas is on the rise. Alternative uses for public space through urban gardening projects have existed in North America since at least the 1970s and 1990s in Europe. More recently, some projects have started including shrubs and trees to provide food, environmental services, personal recreation, and bioenergy. To date there has been little research on the factors that enhance or inhibit the diffusion of such projects. 62 urban agroforestry projects in U...     »