In a study conducted in a Chicago public housing development, women who lived in apartment buildings with trees and grass immediately outside reported greater effectiveness and less procrastination in dealing with their major life issues than those living in barren but otherwise identical buildings. In addition, the women in greener surroundings found their problems to be less difficult and of shorter duration.
Kuo, Frances E. (2001). Coping with poverty: Impacts of environment and attention in the inner city. Environment & Behavior, 33(1), 5-34.