Mature trees generally cope with dry weather better than young ones, but “generally cope” isn’t the same as unaffected — and in a prolonged, intense drought, established trees can and do struggle too, particularly ones in shallow soil, confined spaces, or already under some other stress. It’s not just a young-tree problem.

• Leaf scorch, early leaf drop or wilting in a heatwave is common, and on its own isn’t necessarily a sign of anything serious – it’s often the tree conserving water. But in a prolonged, severe drought it can be an early warning sign rather than a passing phase, so it’s worth watching how a tree responds rather than assuming it’ll bounce back on its own.
• Branch dieback is a more serious sign. When a tree can’t get enough water to all its branches, it prioritises the core of the crown and lets smaller twigs or outer branches die back – you’ll see brittle branches, sparse foliage, or patches of canopy that stay bare.
• Drought stress makes trees more vulnerable to pests and disease, and the effects can persist for a year or more after the weather improves – a tree can survive one bad summer and then decline the following year as the stress catches up with it.
• Don’t prune a stressed tree unless there’s a safety reason to. Pruning is itself a stress on the tree, so unnecessary work during a drought can do more harm than good.
• Signs worth getting checked out: significant crown dieback, bark splitting, branches dropping without warning, fungal growth at the base, or a tree that hasn’t recovered once cooler, wetter weather returns. If you’re noticing any of this on a mature tree this summer, it’s worth having it looked at rather than waiting to see what happens.