Spatial contagion: Gardening along the street in residential neighborhoods

Urban nature, including residential gardens, can promote biodiversity and increase human wellbeing. Understanding factors that encourage the spread of gardening within cities may help planners facilitate healthier and more biodiverse urban communities. This study characterizes the spatial distribution and attributes of gardens found in easement areas of Ann Arbor, Michigan. Spatial analyses of these privately managed public spaces provide evidence of clustering for both presence of gardens and their esthetic quality. Data collected on the location and attributes of easements from 22,562 properties during summer of 2009, show that 11% of these properties held an easement garden. Results of multiple spatial analyses, each targeting a different aspect of garden distribution, show that (a) the most intense easement garden clustering occurs among neighbors with direct visual access to nearest neighbors' easement areas; (b) it is 2.4 times as likely that a property holds an easement garden if a property within 30 m holds one; (c) although clustering is measureable for all neighborhood sizes up to 610 m from home, peak clustering happens within 91 m of home; and (d) clustering of easement gardens are clustered in terms of quality (appeal), and greatest clustering occurs between pairs of adjacent neighbors. While larger scale factors may play a role in where a garden cluster is initiated, the dominant occurrence of relatively small cluster sizes indicates that social contagion is in play. The potential value of social contagion is discussed as a mechanism for spread sustainable behaviors that support ecological resilience in urban areas. (C) 2012 Elsevier B.V. All rights reserved.