Collectively planting garden vegetation for biodiversity: Are hard surfaced gardens and householder unwillingness a constraint?

Domestic gardens constitute important refuges for biodiversity. However, their typical small size mismatches with the larger scales at which species procure resources from urban areas. Consequently, they lack the capacity to enhance biodiversity at these scales. This could be addressed by aggregating garden resources (e.g. vegetation) and increasing garden connectivity. Specifically, this could involve neighbouring householders removing brick walls and fences that segregate gardens and collectively planting vegetation across garden boundaries. Nevertheless, insufficient research has explored 1) how hard surfacing gardens influences native/non-native vegetation presence, which could influence this action’s effectiveness 2) the number of householders willing to undertake such action 3) reasons for unwillingness and how this could be resolved. These research gaps were addressed using an online householder questionnaire distributed weekly to the UK ‘followers’ of four Facebook pages from January to December 2014. From a total of 276 respondents, 220 (84 %) had gardens with hard surface and this had a significant negative association with native vegetation presence. Only 7 (3%) presently collectively planted vegetation, but 152 (58 %) expressed future willingness. Desires to retain garden control and privacy predominantly underpinned unwillingness. In order to increase the effectiveness and prevalence of collectively planted vegetation, more stringent planning policy is required to restrict hard surfaced gardens. Moreover, desires for garden control and privacy need to be accommodated. This could be principally achieved by 1) communicating that little control would be lost as a result of this action 2) segregating gardens with hedges, which benefit biodiversity and simultaneously provide privacy.