Objective <p>The purpose of this study was to implement a comprehensive intervention incorporating agricultural and horticultural activities in a psychiatric hospital, to assess the feasibility of this intervention, and to measure its impact on both staff and patients. We used a mixed-methods approach, including quantitative data from a self-administered questionnaire, qualitative data from meeting minutes, and semi-structured interviews to examine the feasibility and impact of the intervention.</p> Results <p>The implementation of agricultural and horticultural activities within a hospital setting was possible by carefully listening to the preferences and opinions of the staff and by establishing step-by-step multidisciplinary meetings and projects. This approach promoted staff-led agricultural and horticultural activities. Ultimately, agricultural and horticultural activities became programs that could be implemented year-round, and collaboration with another facility was established. Over eight months, emotional exhaustion among staff also decreased, and patients provided positive feedback. The limitations of this study include its single-site design.</p>