A new study from the University of Leeds provides fresh insight into how access to trees and greenspaces can be improved across English cities and includes analysis of four cities within the White Rose Forest.
The “3-30-300″ guidance, proposed by international urban forestry expert Cecil Konijnendijk, recommends that every house, school, and workplace has a view of 3 trees, that there is 30 % canopy cover in each neighbourhood, and that each building has a public greenspace within 300 metres. Researchers analysed the urban neighbourhoods of Leeds, Bradford, Wakefield and York, along with three other cities, and found that at most, only 2% of buildings in any city region met all three components of the 3-30-300 guidance, revealing clear opportunities for targeted tree planting and greenspace improvements.
Trees and greenspaces provide benefits such as improved mental and physical health, reduced urban temperatures, and habitat provision for wildlife. However, existing measures of ‘greenness’ like canopy cover don’t tell us how equally trees and greenspaces, and therefore their benefits, are distributed. By judging the performance of English cities against the 3-30-300 guidance, this new study creates a baseline from which priority areas for tree planting can be identified and progress can be monitored.
Elle Smith, PhD researcher and lead author of the study, said:
“Many cities and urban areas are setting targets to increase green infrastructure and in particular to plant more trees. This is often with the goal of mitigating the impacts of climate change. By aligning new tree and greenspace targets with the priority areas identified in this study, we can make sure we improve access to the full range of benefits, from climate mitigation to improved health and wellbeing.”
The proportion of buildings across the four White Rose Forest cities which met each component of the 3-30-300 guidance are shown in the Venn diagrams below.
Venn diagrams showing the proportion of buildings in the White Rose Forest cities studied that meet each component of the 3–30–300 guidance as well as different combinations of the components. A quarter of buildings across the four cities did not meet any of the components and therefore are not represented in the diagrams.
The performance varies slightly between cities; none of the buildings in York met all three components, while almost 2 in every 100 buildings met all three components in Leeds. York shows the lowest performance overall, and Leeds shows the highest, however both cities perform similarly at the 3-tree component with approximately 66% of buildings achieving this target in Leeds and 62% in York. Wakefield showed the best performance at the 300 m component, with around 30% of buildings within 300 m of a public greenspace. In every city, it is clear that the 30% canopy component is where most improvement is needed, making it a key focus for future action. Overall, the results underline the necessity of the White Rose Forest’s work, particularly the Green Streets® programme, which aims to plant more trees in our urban areas and create a greener environment overall.
Giving each building a score between 0 to 9 for 3-30-300 performance, where 9 means the building meets all three components, the researchers produced maps for each city (see below for Leeds) showing areas performing well and those where there is opportunity for improvement, often found to be inner-city areas.
3-30-300 gradings across the study area of Leeds. Each grid cell is 1 ha, and the grading is the average across buildings within each cell. Where there were no buildings within a 1 ha grid cell, the cell is transparent.
The study also compared performance of the seven English cities to other cities around the world. Although the English cities in this study perform similarly to the international cities for the 3-tree component, the charts below show that the English cities perform relatively poorly at the 30% and 300 m components, reinforcing these areas as key opportunities for improvement.
The results for each component of the 3–30–300 guidance (A-C), performance in all three components (D), and average grading for buildings (E) in each city. The detailed method and a 50 m cut off distance for the 3-tree component were used. Panels A-D also show the mean (black line) and range (grey shading) of results from 3-30- 300 studies in global cities. See Smith et al. (2026) for details of the studies and list of global cities.
Further analysis of the land use of the existing trees in neighbourhoods within these cities revealed which land use types are most important for success at the 3-tree and 30% components. Having lots of trees in private gardens was found to be very important for the 3-tree component while the woodland cover in a neighbourhood was found to be most important for the 30% component. This suggests that planting and preserving trees in private gardens, as well as creating more woodland could improve 3-30-300 success in English neighbourhoods.
Hannah Walker, Urban Forest Research Scientist at Forest Research and co-author on the study, said:
“We know how important urban trees and greenspaces are to people living in towns and cities, and the range of benefits they provide. It’s vital that everyone can experience those benefits. This work builds on the well-established metric of urban tree canopy cover and gives us more detailed insights into how the spatial distribution of trees and greenspaces has an effect on the provision of benefits, at city-wide and neighbourhood scales.
Our study shows that increasing canopy cover across urban areas is still very important, and that there are priority areas in each city where local authorities can look to establish new trees where they are most needed. The roles of trees in private gardens in helping neighbourhoods score highly in the 3-30-300 rule is particularly interesting. This work gives us strong evidence for their importance in providing public benefits and should encourage us all to retain and maintain these existing trees.”
We hope these results will support local authorities to identify where new tree planting and improvements in access to greenspaces will have the greatest impact. In future work we plan to build on these findings and produce different scenarios of the best places to plant new trees to maximise success at the 3-30-300 guidance while meeting the local authority canopy cover targets set out in the White Rose Forest Strategic Plan for 2025-2050.
This research was a collaboration between the University of Leeds, University of Edinburgh, Forest Research, the National Library of Scotland and the White Rose Forest. To find out more about forest related research at the University of Leeds, visit our website: https://leaf.leeds.ac.uk/
The research was supported by the Natural Environment Research Council (NERC), including a SENSE CDT studentship. Full details of the research are available as Open Access via Urban Forestry and Urban Greening