A number of population-scale studies have emerged in the past few years to suggest that areas in cities containing more street trees have better mental health, even after taking into account socio-economic factors. This has led to a policy push for prescribing nature to improve mental health. However, there is still a substantial knowledge gap concerning the mechanism through which these benefits from nature are delivered.

We used street tree data from Birmingham City Council and the Small Area Mental Health Index to examine the effect of the configuration, colour, and volatile organic compound emissions of street trees compared to other green space metrics on mental health in the city of Birmingham, UK.