Implementing generationally appropriate activities for persons with dementia is a challenging task. Horticulture therapy (HT) addresses this challenge through the use of plants to facilitate holistic outcomes. Utilizing the model of environmental press, the current study sought to analyse adult day service (ADS) participants' responses to HT as compared to traditional activities. HT activities were conducted once a week for a half an hour at four different ADS programs over the course of 9 weeks. Observational data were collected during HT and traditional ADS activities using a modified dementia care mapping (DCM) technique. Observers coded predominant behavioural and affectual responses for each participant. HT activities facilitated higher levels of productive engagement and positive affect and lower levels of non-engagement than did traditional ADS activities. Therefore, HT offers dementia-care staff a viable activity alternative that is well received by clients and inclusive of all interested persons, despite cognitive limitations.