New research from the RHS and Frank P Matthews tested 19 garden tree species at RHS Garden Wisley to see which ones deliver real climate benefits. The study measured cooling, transpiration, carbon storage, pollution mitigation, wind shelter and pollinator support. Flowering cherry (Prunus 'Fugenzō') stood out for cooling because it kept transpiring at 35°C, while Callery pear, red maple, Italian cypress and western red cedar also performed well. Other species had specific strengths: Italian cypress was best for rainfall storage and wind screening, hawthorn helped with waterlogged soil, and Callery pear led on carbon sequestration. The researchers caution that the trials ran under irrigated conditions, so drought performance is not yet clear. For anyone choosing trees for gardens, streets or development sites, the findings are a practical starting point for selecting species that cool and shade rather than just look good.
