Posted: 07/10/2013 at 13:49
Many thanks for your responses.
The hedge is 9ft tall and is about 50 years old. The soil is fairly dry at the surface and clay much deeper. The garden was watered regularly but obviously (taking your comments on board) not enough! I'll be placing lots of horse manure around the base of each tree this coming week and water it in thoroughly. I hope this will help.