hi Ann

we bought two this year and they're still flowering but hadn't thought that pruning was necessary. If you need to keep them in trim then winter appears best.

Ann Willers

Hi

Bottle brush, Callistimon do not need pruning as such. Some people lightly prune  to keep the shape or if the odd branch has overgrown. Best time to do it is after flowering.

Bazza

I only prune the bottle brush after it has finished flowering.

 I usually cut just underneath where the flower bud comes from; and it does the trick!!

My bottle brush is about 3 years old and growing well as a result.

Dont forget to water well in hot dry weather.