Conclusion
Our results support the increasing understanding that nature-based interventions have a positive effect on mental wellbeing in primary care patients. In green surroundings, prescribed nature-based interventions or group exercise can improve perceived health and ability to function. Improved mental health and positive mental wellbeing was observed only in the Nature-group. Based on the observed differences in improved mental wellbeing depending on perceived health, we would recommend either sports or nature-activity for those initially feeling healthy, and nature-based intervention especially for those rating their health as poor.