"jks" wrote in message
...
My Leylandii have been dying one by one for several years. Previously they
took some time to die but the latest was quite healthy 2 weeks ago and is
now dead. All the trees, planted about 16 years ago, were on a bank of a
stream so I don't think water was a problem.

Looking beneath the bark there is no sign of fungal disease and I can't
see any aphids on it.

It looks as if a privet bush close to the hedge is also dying.

Anyone know what the problem might be and have a cure?

It may be your neighbour poisoning them. Hooray