What Could THIS Be About?

Herewith (what we believe to be) our Golden Mexican Orange Blossom bush; as you see, some of it is diseased; we took a sample to our garden center who suggested it was nothing to worry about, but due to exceptionally damp conditions; as it has been going on – off and on – for a couple of years, we fear something more sinister might be going on; does anyone know what this is and what the remedy could be?

Many thanks,

Lao

 

I've seen similar on mine, I usually cut it out and it doesn't seem to get worse.
I've never really looked into what might be causing it.

Some kind of disease girdles a stem and everything above it dies.

 

I'm putting off cutting out the frosted bits on mine for a month or so, in case we get more hard frost, I think we got close to minus 5c last night, so not good.

But its obviously not frost on yours Lao as the rest of it is untouched.

 

The two bugbears of Choisya are cold damage and root rot. The fine-leaved varieties Aztec Pearl, Greenfingers and Goldfinger are a lot less susceptible to frost damage and I've not had any problems with die back on those. The ternata varieties are a dead loss here, though....I've only managed to keep one Sundance alive under a big Acer so I suspect that the tree keeps the soil dry in winter. As pete says, they respond to pruning out the dead branches.

 

Thank you, everyone; overall reassuring, really. We'll trim the die back as you suggest.