On Thu, 9 Oct 2008 22:10:05 +0100, berry
se wrote:


We have a great many Pyracanthas of various types in the garden, all
growing against walls or fences and in good condition. Earlier this
year one of a pair on either side of our front door started to die off
on one side, and is now almost all brown wood with the occasional green
leaf.
The odd thing is that it is only one branch of the main plant and the
rest of the shrub is in fairly good shape.
I am anxious to find out if it can be saved, but have no idea what the
problem is.
I have a small, wall-mounted pot in which are flowers, depending on the
season, around which the pyracantha grows. Woodlice and snails tend to
climb the pyracantha and sit on or behind this pot so I regularly treat
the wall and the pot with ant/woodlice powder which gets onto the
pyracantha when it rains.
I have also noticed in past years that the plant has been covered in
ants and aphids.
The plant on the other side of the door (which is of the same type of
red-berried pyracantha - I don't recall which they are as they have
been in for some years) is in excellent shape. It is vigorous and has
no sign of any problem. This, too had the aphid infestation (though
not so badly) and I treat the pot around which it grows in the same way
to deter the woodlice etc.
These are the only things that I can think of that might have had an
effect, but wonder if anyone else has had a similar problem. If so,
what should I do?
I am loathe to cut the bad wood out as it is a major feature around our
door and would like to save the plant if I can


This may be a false lead, but I know that pyracantha is susceptible to
a disease called fireblight. try goggling for that, see if it seems
appropriate.

Add ucdavis to the search, they give out lots of advice on lots of
plant related things.