You prune after flowering, just below the flower (assuming you do not want seed). In the UK they are half hardy (H3), and will need full sun next to a south or west facing wall.

Many thanks Botanic, I will leave it until it flowers. I did that last year and didn't get many blooms and have since read that you should pinch off the new spring growth at the tips? Is this something you are aware of?

It makes a hedge plant in warmer parts of the world, much like Hawthorn. If you pinch new growth you will have a compact plant. It flowers on last years wood, so you may pinch off flowers but you have a more compact plat.

I only prune my bottlebrush when it is spreading out too far. I do this by cutting out the offending piece right back at its base. I finish up with a shrub that retains its shape, but is not so broad, and can be done at any time of the year.

Many thanks guys, that makes absolute sense. Thankyou so much for your quick responses. All I need now is some sun..... Best regards.