It should be showing all new flower bud for next year so to prune it now would be to lose next year's flower. Immediately after flowering would be the best time (June/July). If you do prune it now, the possibility is that it will make some new growth which will be at risk from the first frosts (don't want to talk about them yet!). It's one of those shrubs that doesn't quite fit the pruning regimes described in the books, because it's not from this country, but use to the milder winters of Chile. Beautiful shrub for a sheltered slightly shaded wall.

Many thanks.How hard to I prune this shrub?

Querying the need to. If you have to, then you can orune it quite hard, but I do little more than shape the ones I've got.

Many Thanks