Posted: 15/05/2013 at 06:39
No, it will delay them but not stop them. But they don't have to be trimmed back every year - if they're not getting too big you could leave them this year. Floribundas don't need heavy pruning anyway. Just check for any dead-looking or thin and twiggy stems and take them out and leave the rest. Give them a dose of Blood, Fish and Bone or proprietory rose fertiliser and they'll be fine.
You can always cut them back a bit when you dead-head them, as long as you're careful not to remove buds.
Just remember to do them in March next year.