This was how one of our Cotoneasters looked last autumn. The intensity of the red foliage colouring always varied from one part of the shrub to another, so it seemed perfectly healthy to me. During the following weeks, the blackbirds stripped the berries, just as normal, and I didn’t suspect anything amiss at all.
I was ready to cut the whole plant down and dig it out, on the basis that the most likely thing to have afflicted it was probably honey fungus, which we have here (it tends to take out individual plants, almost randomly it seems, and mercifully not very often). Cotoneasters are known to be susceptible to honey fungus, and it seemed the most likely explanation. But in the past few weeks, it has actually started up again, so I am going to cut it back to just in front of the new branch and hope for the best. The little new branch does look extremely healthy. Would it look healthy, indeed would it be there at all, if the plant had been clobbered by honey fungus?