ceanothus Leafs and branches turning black
Can anyone advise why this might be happening?
I can't see leaves turning black, I can't see the branches properly, but I suspect it is not so much the branches turning black, but possible Scale infestation on your shrub. Take a closer look and use a small knife and try to see if you can scrape them off the branches. If they come off, it's possibly Brown Scale.
You will need to remove them. If they are soft, you can set your hose on jet to blast them off. Other options could be to scrape them off.
So long as your shrub is growing in optimum conditions - planted in free draining soil and watered well in the first few years, and get plenty of sunshine, they should recover.
Ceanothus seem to have a relatively short life,8-10 years from my experience. Two things that can bring on bad health early is moving the plant from its original position and any pruning that requires secateurs or loppers,the bigger cuts seem to attract disease. You could try spraying a couple of times with s b invigorator.