Ouch! Any signs of damage on the stem where it meets the trunk? It looks like either stem or serious root damage...you've not been digging around the roots to plant things and chopped through a main root have you? I hope the rest of the tree will be ok..looks like you may have lost about half of it there.....sorry :(

Hi there, no there is no damage on the stem that's the puzzling thing, it was the first thing I looked for, I have 2 big dogs and my first thought was that one of them had perhaps chased a squirrel and crashed into the branch but no and I haven't planted anything or been digging anywhere near the tree, starting to think disease of some kind? :0(
Thanks.

Whatever the cause the best thing may be to cut off the dead branch altogether almost back to the junction with the main tree and burn it in case the cause is viral. If other branches begin to die back in the same way it would probably be best to remove the tree and not replant in the same place for a few years. When you cut off the affected branch have a look at the cut area to see if there is a darker mark or staining on the wood.

Probably best to do it asap as well, as silver leaf can be an issue with pruning plums if you leave it too late. What a pity. :( i love plums too!

Hi, thanks for the advice, I will go and cut the branch off, it's typical isn't it, I'm not really an apple fan but our 3 apple trees are laden with fruit this year and are so healthy (which is great of course) but plums are my favourite, grr! the joys of gardening I suppose.
Thanks again.

The deed is done :0(..................fingers crossed for the rest of the tree.
Thanks again.
Phoebe

Ps. No dark staining in the wood.

Well, that's good news Phoebe. I've no plums on my trees, and the apples are almost all blown off now! ...sigh...back to the supermarket for the both of us!

Still, we do get pleasure out of gardening regardless.

Oh yes :)