Reduced mowing frequencies increase pollinator abundance in urban lawns in the UK

Insect pollinators are currently declining, in part due to the loss of habitats and foraging resources. However, one potential source of refuge is lawns in urban areas and the floral resources within them. Lawns represent a substantial proportion of urban green space and, if managed with pollinators in mind, could become a major component of a matrix of foraging resources. This study used Ministry of Justice prison and court sites as a case study for the management of urban lawn space. Sites contained four patches, one control patch mown as normal every two weeks and then three patches mown either every four, six or 12 weeks. Weekly pollinator and flowering plant surveys were completed at each site over 12 weeks from June – August 2023. We found that patches with less frequent mowing (every six and 12 weeks) had a significantly higher abundance of pollinators, >170% higher than the typically used mowing frequency of every two weeks. Lawns left unmown for 12 weeks also had higher floral species richness and flower cover than lawns mown every two weeks. Consequently, we recommend that lawns within urban and suburban building complexes are mown at an interval of at least six, but ideally 12, weeks to improve floral resources and pollinator abundance.