Fourteen people attending an adult day programme were recruited to a structured horticultural therapy programme which took place over 10 weeks. The effects were assessed using Dementia Care Mapping and questionnaires completed by family carers. High levels of wellbeing were observed while the participants were engaged in horticultural therapy, and these were sustained once the programme was completed. This study adds to the growing evidence on the benefits of horticultural therapy for people with dementia who have enjoyed gardening in the past.