All about the ‘wow factor’? The relationships between aesthetics, restorative effect and perceived biodiversity in designed urban planting

Urban populations experience the multiple health and well-being benefits of nature predominantly via urban green infrastructure. If this is to be designed and managed optimally for both nature and people, there is an urgent need for greater understanding of the complex relationships between human aesthetic experience, well-being and actual or perceived biodiversity. This integrative study assessed human aesthetic reaction, restorative effect and perceived biodiversity in relation to fine-grained categories of woodland, shrub and herbaceous planting. We surveyed 1411 members of the public who walked through planting of varying structure, species character and percentage flower cover whilst completing a site-based questionnaire. Semi-structured, in-depth interviews were then carried out with 34 questionnaire participants. Correlations between perceived attractiveness and perceived biodiversity were identified for three out of four biodiversity indicators. There was a correlation between perceived attractiveness and restorative effect yet this was not strong. Colourful planting with flower cover above a critical threshold (27%) was associated with the highest level of aesthetic preference. Subtle green ‘background’ planting afforded a restorative effect. These results are discussed with reference to the Circumplex Model of Affect. Our findings indicate that people appreciate colourful flowering public planting for the ‘wow factor’, but that green planting outside the narrow flowering season of most species is greatly valued. Planting moderately or most natural in structure was perceived as significantly more restorative than that least natural in structure suggesting that people in the UK may be increasingly accepting of a messier ‘ecological aesthetic’ in urban planting.