Which trees matter most? The role of private garden trees and woodland cover for 3–30-300 success in seven English cities

The 3–30–300 rule is a tool to evaluate access to trees and greenspaces and is gaining popularity in Europe but not yet in the UK. We calculate a 3–30–300 score per building to measure success at the rule in the local authority areas of seven English cities, examining how overall canopy cover and where the canopy is situated (e.g. woodland, street, private garden) influence performance. We find that a maximum of 2.1 % of buildings in the locations studied meet all three rules. Land use analysis indicates that increasing the density of trees in private gardens and increasing woodland cover are the most important factors for improving performance at the 3-tree and 30 % components in UK neighbourhoods. These recommendations should be applied to UK urban areas to improve overall performance at the 3–30–300 rule and increase access to trees and their benefits. We also explore how sensitive the results of the 3–30–300 analysis are to methodological choices by comparing results of network and line-of-sight analyses to simple buffers for the 3-tree and 300 m components of the rule, finding that more simple methods result in higher 3–30–300 scores and therefore suggest better 3–30–300 performance.