The mental health benefits of hands-on participation in urban afforestation activities

Despite extensive research on the environmental benefits of urban afforestation, its direct impact on mental health through active engagement remains underexplored. The present study aims to investigate the potential benefits of hands-on participation in an urban afforestation program on affective states and subjective vitality. This study was conducted as a single-group, pretest-posttest clinical trial. One hundred fifty-two healthy adults participated in a tree-planting activity. Affective states and subjective vitality were assessed using the Positive and Negative Affect Schedule and the Subjective Vitality Scale, respectively. Several potential predictive factors regarding the expected effects of this program were recorded, including the connectedness to nature, instorative properties of the environment, and physical effort exerted during the activity, along with lifestyle habits such as daily physical activity and sleep duration. Results indicated increases in scores of the positive affect subscale ( t= −9.165, p <.001) and the Subjective Vitality Scale ( t= −5.881, p <.001), as well as a decrease in the score of the negative affect subscale ( t= 7.473, p <.001). Multiple regression analyses showed that after controlling for baseline scores, several predictive factors uniquely explained an additional 14.9% of the variance in positive affective states, 2.2% in negative affective states, and 11.6% in subjective vitality. In conclusion, hands-on participation in an urban afforestation program appears to favorably influence affective states and subjective vitality in healthy adults. Understanding that these psychological benefits arise not only after the trees grow, but also throughout the planting process itself, could encourage city residents to engage in such activities. • Hands-on urban afforestation enhanced positive affect states and vitality. • Active engagement in tree planting reduced negative affect states. • Perceived instorativeness and connectedness to nature influenced the outcomes.