Barriers and opportunities for further enhancing urban garden biodiversity: Insights from a behaviour change model for the United Kingdom

Abstract Urbanisation poses a major threat to biodiversity, yet residential gardens offer opportunities to provide key habitats for urban wildlife. Understanding both the perceived feasibility of implementing further improvements to gardens for biodiversity and the barriers that constrain engagement is essential for designing effective conservation interventions. This study uses a questionnaire survey of 231 householders in Great Britain to assess the likelihood of adding 10 wildlife‐friendly garden features and to identify perceived barriers using a behaviour change framework which considers capability (C), opportunity (O) and motivation (M) as determinants of behaviour (B) (COM‐B model) Within a sample of gardens, in which most already contained at least one wildlife‐friendly feature, the overall odds of respondents implementing further improvements were low, indicating a 37.5% probability of engagement. Wildflower patches were the only feature rated as more likely than unlikely to be implemented, while compost heaps and ponds were the least likely. All COM‐B barrier subgroups significantly reduced the likelihood of engagement, with physical opportunity constraints (67.9%), particularly a lack of space, and psychological capability (20.5%) being the most prevalent, followed by social opportunity (6.2%) and physical capability (5.4%). Younger respondents and those from more socio‐economically deprived areas reported more barriers. Given that many surveyed gardens already contained wildlife‐enhancing elements, limited space, the level of effort required, associated costs and existing knowledge were key obstacles to further improving gardens for biodiversity, even among a potentially conservation‐aware group. Our findings indicate that the presence of existing conservation efforts does not necessarily predict householders' engagement with additional biodiversity interventions. Individuals report substantial barriers to engagement; therefore, we recommend that conservation non‐governmental organisations (NGOs) coordinate efforts that target higher‐level stakeholders, enabling resources to be reallocated towards addressing barriers through top‐down policy change. Policy‐led interventions have the potential to overcome barriers to individual householder engagement, thereby improving biodiversity outcomes at a broader spatial scale. Applying these insights in policy and practice could enhance urban gardens as key contributors to biodiversity conservation. Read the free Plain Language Summary for this article on the Journal blog.