In article .com,
"cliff_the_gardener" writes:
|
| As a tree they are relatively hardy, but they can get a fungal disease
| called coral spot - the bark gets these coral coloured spots on it.
| Can be fatal, but helped by good air circulation

It's almost never serious - it normally attacks only dead wood,
though some sources say that it can cause die-back. As far as
I know, there is no definite evidence that it DOES cause such
die-back, as distinct from being the first invader after the
branch starts dying back from another cause. It will infect
newly cut branches within a week or two in warm, wet weather,
so either hypothesis is possible.

Anyway, as you say, whatever the original cause, a good first
treatment is to improve air circulation.


Regards,
Nick Maclaren.