Watering Strategy, Collective Action, and Neighborhood-Planted Trees: A Case Study of Indianapolis, Indiana, U.S.

A growing number of municipalities and nonprofits work with private citizens to co-produce the public benefits associated with urban forests by providing sizeable young trees to neighborhoods that agree to plant and water the trees for the critical first few years after planting. Little research has addressed the effectiveness of such programs or the extent to which variation in neighborhood maintenance and watering strategies may be related to biophysical and social outcomes. Without such knowledge, tree-planting investments are at risk of being a sink of public or charitable funds. This paper presents a case study of Keep Indianapolis Beautiful, Inc.’s neighborhood tree plantings in Indianapolis, Indiana, U.S., where researchers explored the relationship of neighborhood watering strategies with planted-tree outcomes, and with subsequent collective activities. The study authors observed neighborhood variation in whether trees were watered by individuals or collectively (groups of individuals), whether signed watering commitments were utilized, whether monitoring of watering occurred, and whether monitoring and subsequent sanctioning (when necessary) changed watering behavior. Results demonstrate that collective watering, signed watering agreements, and monitoring/sanctioning that changed behavior were positively associated with tree survival. Collective watering was also positively associated with subsequent collective activities, such as a neighborhood clean-up or block party. Such findings can improve the guidance offered by municipalities and nonprofits to neighborhoods for the management of successful tree-planting projects, and can ultimately improve the survival, growth, and thereby benefits provided by neighborhood-planted trees.