All trees are brown, on a summer’s day

My trees have gone brown due to the heat. What should I do? N Beacher, Winchester, Hants

DAVID: It’s important not to cut trees back that are under stress due to heat, as this could stress them even more.

Focus on giving them a long drink over several hours. Sink an upturned plastic bottle into the ground beside each tree, with holes in its lid and the base cut off.

Keep filling these so water seeps slowly to the roots.