My question, i planted about 40 horse chestnut trees (10 years old) in October 2007, they thrived last year and had beautiful flowers early this year but since the hot spell the leaves are browning and appear to be dying. I’m now watering them but there does not seem to be any revival? will I fertilize the water? was it the sudden heat that caused this? will this set back my trees or worse? also my lime trees leaves are suffering but the ash and willow’s are grand. My site is over 6 acres so they’ve loads of room and there are plenty of other trees around/in area.
Watering will help but heavy watering (20 – 40 litres per tree) needs to be applied,  three or four times at ten day intervals should be enough. Give no feeding. Chestnuts will often make new growth in summer.
The speckling may have been caused by horse chestnut leaf-miner, the larvae of which burrow in the leaves. This is occasional but becoming more common. It is disfiguring and weakens trees but it is not fatal.