Posted: 28/06/2015 at 18:38
If they get too big and straggly they don't always come back too well after a brutal haircut, Lyn. The bigger the leaf size, the less tough they are usually. Best to do it in stages and see what happens. I've hacked back Red Edge successfully in a previous garden though, with no ill effect.
Curmudgeon - they need to be trimmed lightly after flowering to keep them at their best. Not too big a hardship unless you have thousands!