Pyracanthus
By Celiamary
United Kingdom 
Thanks for suggestions. It does look rather burnt. I will try and provide a photo (if I can figure out how to do this) but in any case it will probably be in a couple of weeks time so I will post the question again at that time.
Pyracanthus, potted, about 15 years old. Berried very heavily this autumn although strangely the berries have not been stripped by blackbirds as usual. Instead, in mid-winter berries and leaves have entirely blackened and withered, from the lower parts moving now to the top of the plant. No previous problems although the plant has never been vigorous in growth, and remains about 5' high and little sideways growth, with no pruning. Is it being killed by the wet conditions, or could it be a disease? Thanks - Celia
3 Jan, 2016
Answers
It might have developed Scab(which I present as an alternative) from prolonged damp conditions in both soil and air. I do not know what can be done to help it recover. Perhaps other members do. Scab is a fungal disease and the other possibility of Fire Blight is caused by a bacteria. From what I have heard from other members in the UK is that you have had a long period of mild weather either damp or wet so that's why I homed in on scab though Fire Blight can be transmitted under the same conditions.
3 Jan, 2016
That is why I suggested a photo.
3 Jan, 2016
If its in a pot which has drainage, its unlikely to be a problem with damp soil, unless the drainage holes have been blocked. But if its been in the same pot for some years, its probably succumbed to the unequal struggle of not being able to develop its root system to a suitable size in order to remain healthy. If its not a dwarf variety, its done remarkably well to carry on living for 15 years when so restricted...
4 Jan, 2016
I would go for fireblight. The only remedy open to you would be a Bordeaux Mixture (copper) spray. I would then think about a heavy prune, a good mulch and a feed in the Spring. Being in a pot will always put it under greater stress than one planted in the ground.
4 Jan, 2016
15 years in a pot, probably never been repotted so compost will be compacted therefore no air reaching the root system. Could be drought even though it has been pi...pouring down with rain. Rain cannot penetrate badly compacted soil. Plant will be stressed and probably has been for several years.
Stressed plants are very prone to disease.
I hate to say this but from your discription it sounds like Fireblight.
I have a vauge recollection from about 20 years ago that Fireblight was a very real problem, easily spread and was destroying Englands ancient Hawthorn hedgerows in the South of England (part of Englands National Heratage).
If I recall correctly. Fireblight was a notifiable disease. I don't know if it still is though.
I hope this hasn't spoiled your day.
22 Jan, 2016
If it looks as if someone has set fire to it then it could be the dreaded Fire Blight, to which Pyracantha is very prone.
We need a picture to help better.
3 Jan, 2016