I'll try that. Only a few are blue though, there are more brown ones!

Has it been dry over winter where you are or on a well draining slope? These are superhardy shrubs but do need moist soil on the neutral to acidic side. As it sounds like you have had it for some time you will know that the older growth can go brown with time.

Plenty of possibilities, other than cultural ones. Any sign of black fruiting bodies anywhere? Any sign of cankers, or raised nodules on the stems? Does it have a heavy infestation of Juniper scale? If none of these, phytopthera might still be to blame - we've always had other varieties of this around, most commonly causing root rot.

I've had a good look at it but can't pin anything down specifically, It seems to be dying from the inside out. No scale nodules or cankers as far as I could see but I'm no nodule expert so might have missed them. . The really dead branches look smooth and purplish where the bark has come off but I tried stripping some bark from a cut off branch with bark still on and it looked normal. . It might have got rather dry last summer - its on top of a four foot bank and doesn't get watered but its been happy there for about six years and has reached a good six feet across- it lived in a biggish pot before that. The pH is 6.5. Looking at it again the whole plant looks rather poorly - if it was a person you would say it looked pale and tired! I think maybe its time has come. Possibly euthanasia is the best treatment while Erica plants are still in the nursery!

I hate it when an established plant suddenly decides the game is up..So hard to tell why sometimes. The only thing i can suggest is a severe cut back of all the brown bits and if there is anything left top up around it with compost and give it a good watering. Or use the opportunity for a visit to the GC.

I don't think there will be very much left - the worst bit will be digging it out because of the place its in. But it would be nice to know what's the matter with it.

And my established skimmia is also on the way out. I had two next to each other. The first one finished dying the year before last and the second bigger one is following very slowly a branch at a time. There is enough left to last the summer and possibly next winter but then alas its what shall I put there instead time.

Thank you everybody for answering so quickly, you are such lovely helpful people. Maybe I should give up gardening and take up meditation....

Sometimes you have to bite the bullet and get rid, grub it out along with those skimmias, if they aren't pleasing to the eye then start again with something new, grub them out with a sturdy mattock dig out the exhausted soil and refresh with some decent stuff and re plant with a new planting scheme, you will feel a whole lot better for doing so.

When you do dig it out, check the roots, see if you can see anything obvious there.

My sister used to have a book of Play Ideas and Things to Do. I think this blog would make a nice second edition!!
Time for OH to make one of his rare forays into awkward corners I think. If there's anything obvious on the roots I'll let you know. Julien digging out much of the exhausted soil in that position would need a small helicopter but I'll bear it in mind!

Well we got it out today after a long struggle. The roots looked OK. There were no nodules. The bark was peeling from the older stems but I guess thats normal? The only thing I could see was a few very small patches of mould on the old stems, and a thin coating on a couple of small branches that were looking as if they were on the way out - this was what was making the needles look blue.
I'll add some compost from the heap and put some Ericas in - need something that looks after itself in that position!

I really appreciate everyones helpful suggestions.You are lovely people!