A tree is a wonderful addition to any size or style of garden, but as our climate changes, we may need to think more carefully about which types we choose
WORDS TONY KIRKHAM
The UK may have escaped the worst of Europe’s extreme heat this summer, but September’s heatwave, which saw a record-breaking five consecutive days of temperatures reaching 30°C, was a reminder that our climate is changing. By 2080, it’s predicted summer mean temperatures will rise by 2.5-4.2°C, rainfall will fall by up to 40 per cent in southern England, and winters will get warmer and wetter, leaving us with drought-stressed trees, and more pests and diseases to place additional pressures on our established treescape.
Where once we might have focused primarily on a tree’s seasonal ornamental attributes when selecting a species for our gardens, now a tree’s drought tolerance or its tolerance to short-term waterlogging will be key. Luckily, the ever-increasing research and information available to us will make it easier for us to select and plant the right tree in the right place.
It’s clear that we need to think outside the box, planting a more varied range of trees, including more non-native species, and integrating these with natives in the landscape. With more than 3,000 different temperate tree species from around the world that will grow successfully in our climate, the choice is endless, but we must get the selection process for the soil types and climate correct if we are to be successful. This criterion or ‘tree ecophysiology’ will help us to build a more resilient treescape that will cope with all the issues associated with climate change into the future, and be less reliant on irrigation.
We’ve seen an increase in pathogens affecting our native trees, meaning there are only around 35 to 40 true British natives to choose from. We also seem to be set on planting the smaller, short-lived pioneer species, such as birches (Betula pendula), alder (Alnus glutinosa), cherries (Prunus avium and P. padus), rowan (Sorbus aucuparia) and crab apples (Malus sylvestris). Possibly this is because they are cheaper, easier to grow, and quicker to establish than the larger trees, but many of these will struggle in the drier conditions now co
