My fifteen year old Silver Birch, planted as a very young tree, is sickly.
It is some 25 feet high and has lost its leaves at its apex and at the
extremities in other places. Other leaves are smaller than they should be
and with evidence of slight choruses. The tree is less furnished with leaves
than it should be. There is no evidence of insect or viral/fungoid
infection. It was planted on the site of a 150 y.o. beech which came down in
the Great Storm. Up to now it has flourished. We are on chalk and it is
surrounded by a beech hedge and shrubs ( buddleia, lilac which are
flourishing), it is some 10 feet from and five feet above a lane which is
heavily trafficked in rush hours. It is three feet above and 35 feet from
our cess pit. It has been gently fed with mild fertilizers to prevent over
feeding and scorch etc and well watered - we are on chalk. We are well up
on the South slope of the North Downs and its position is exposed - but this
has not effected another some 150 yards away at the top of the garden.

Has anyone any ideas/suggestions?

PeterP