A recent study published in the HortTechnology journal has found that “gardeners have lower levels of self-reported depression, anxiety, and stress when compared with those who did not identify themselves as gardeners.” 
The research was undertaken by researchers at Texas State University, Mississippi State University and the University of Mount Olive. The study was undertaken during the COVID-19 pandemic with “the purpose of this study was to evaluate the impact of gardening and outdoor activities during the COVID-19 pandemic on perceptions of hope and hopelessness and levels of anxiety, stress, and depression.”. The study included 458 participants who completed a Depression Anxiety and Stress Scale (DASS-21) inventory and a Hope Scale with 299 self-identified gardeners and 159 non-gardeners.
The gardeners were found to garden in home gardens (41.3%), community gardens(2.6%) and many also had interior plants (44.3%) and container gardens (24.8%). The hours of gardening ranged from 1 hour to 4 hours a week during the COVID-19 pandemic. Interestingly, 22.5% of gardeners had spent more than 7 hours or more gardening per week prior to the pandemic.
When comparing gardeners with non-gardeners it was found that non-gardeners had more anxiety, stress, and depression. Also, it was noted that gardeners were found to have a more positive Hope Scale. The study also surveyed participants on their types of outdoor activities including (walking, boating, yoga, biking, tennis, soccer, etc. It was also found that those who were outside more often had lower depression, anxiety and stress as well as more positive Hope Scale scores.
The study does have some limitations as it included those who volunteered to participate and had access to the internet. However, for landscape architects, this study reinforces some of the anecdotal evidence (and previous studies) that spending time outdoors and gardening can reduce depression, anxiety and stress as well as an increased sense of hope or well-being. The “research also highlights the importance of access to green space and outdoor activities such as gardening. This is particularly important for those living in metropolitan areas where green space might be less available…..”. 
 Johnson, M., Waliczek, T. M., Etheredge, C., & Bradley, J. C. (2023). The Connection between Gardening and Outdoor Activity during the COVID-19 Pandemic and Perceptions of Hope, Hopelessness, and Levels of Stress, Anxiety, and Depression, HortTechnology, 33(2), 168-175. Retrieved Feb 6, 2023, from https://journals.ashs.org/horttech/view/journals/horttech/33/2/article-p168.xml