The climate is changing British gardens everywhere. Well, almost everywhere. The Royal Horticultural Society has modelled how global heating will affect its property until 2075 and discovered that summers will be hotter and drier in all its gardens – except in Manchester.

Greater Manchester’s renown as a rain trap – there is even a website tracking rainfall, called Rainchester – means that the RHS Bridgewater garden in Salford is being earmarked for species that thrive in a cooler, wetter climate.

Trees including oaks, birches and beeches that have been part of the British landscape for centuries are starting to suffer in southern England, so are being considered for RHS Bridgewater’s new arboretum, a botanical garden aiming to preserve a wide range of species…