Background and objective: The elderly living in homeless living facilities for a long time suffer from various mental health problems. This study aims to determine the psychological, emotional, and social effects of a horticultural therapy program composed of gardening activities, which was designed based on the semantic structures of life for the homeless elderly living in the facilities for a long time. Methods: A total of 12 subjects (6 in the control group and 6 in the experimental group) participated in the study. The horticultural therapy program consisted mainly of gardening activities, and a total of 16 sessions were conducted once a week for 16 weeks, 60-90 minutes per session. The subjects were tested to evaluate their self-esteem, depression, and horticultural activities. The data were analyzed using the Mann-Whitney U test, Wilcoxon rank test, and Friedman test, which were nonparametric tests, conducted at a 95% significance level. Results: First, in the case of self-esteem, a significant difference was found between the groups, 20.00 points (SD = 5.69) in the control group, and 25.50 points (SD = 3.73) in the experimental group (p = .034). Second, in the case of depression, no statistically significant difference was found in the posttest. Finally, in the case of the horticultural activity evaluation, the scores of most variables gradually and significantly increased during the program [Verbal interaction during activity (p = .006), Self-concept and identity (p = .006), Need-drive adaptation (p < .001), Interpersonal and social relations (p < .001)]. Conclusion: These results support that the horticultural therapy program could help the elderly improve psychological relaxation, emotional stability, and social relationships. In order to generalize the results, it is suggested to increase the number of subjects or conduct additional repetitive experiments in further research.
