Sowing the seeds of wildlife-friendly gardening: does a garden biodiversity assessment promote uptake of pro-biodiversity gardening behaviours?

Abstract Residential gardens have the potential to support native biodiversity across cities. Certification programmes designed to motivate residents to perform pro-biodiversity gardening actions require a formal process of garden biodiversity assessment. We evaluated whether a garden biodiversity assessment process was effective at motivating pro-biodiversity gardening behaviours. A one-off garden assessment accompanied by feedback was trialled on 89 residents in 2020/2021. Four years later we surveyed this group and a matched control group to determine whether the assessment had a motivating and long-lasting positive effect on pro-biodiversity gardening. Results were mixed: while 57% reported the assessment did not influence subsequent gardening decisions, 38.5% confirmed that the assessment process had motivated the changes they made and 56% said it helped them understand at least a little better how they could enhance biodiversity in their garden. This understanding was positively associated with how useful they rated their tailored feedback but was not associated with their biodiversity score. The two groups didn’t differ in the extent to which biodiversity enhancement was considered when making changes, and a larger proportion of the control group made biodiversity-positive changes. The number of changes made was not associated with age, income, education, years at the address, bird knowledge, or environmental engagement, but was positively associated with their nature connection score. While we provide some evidence to support the use of biodiversity assessments, ongoing support in the form of collaborative partnerships between gardeners and local government could be more effective at achieving favourable biodiversity outcomes.