Effects of Horticulture on Frail and Prefrail Nursing Home Residents: A Randomized Controlled Trial

Objective: Frail nursing home residents face multiple health challenges as a result of their frail status. The aim of this study was to examine the effects of HT on the psychosocial well-being of frail and prefrail nursing home residents.

Design: Randomized controlled trial.

Setting: Nursing homes.

Participants: One hundred eleven participants were randomly allocated into the intervention [horticultural therapy (HT)] and control (social activities) conditions.

Intervention: HT group participants attended a weekly 60-minute session for 8 consecutive weeks. Control group activities were social in nature, without any horticulture components.

Measurements: The outcome measures include happiness, depressive symptoms, self-efficacy, well-being, social network, and social engagement. The time points of measurement were at baseline (T₀), immediately postintervention (T₁), and 12 weeks postintervention (T₂). A modified intention-to-treat approach was adopted. A multivariate general estimating equation was used to analyze the data.

Results: Forty-six and 50 participants received at least 1 session of the intervention and control condition protocol, respectively. A significant interaction effect between group and time was observed only on the happiness scale (β = 1.457, P = .036), but not on other outcome variables. In a follow-up cluster analysis of those who received HT, a greater effect on subjective happiness (mean difference = 6.23, P < .001) was observed for participants who were happier at baseline.

Conclusion: HT was found to be effective in promoting subjective happiness for frail and prefrail nursing home residents. Its favorable effect suggests that HT should be used to promote the psychosocial well-being of those who are frail.