The leaves will reappear next season all over the stems, so no need to prune for that reason :-) If you want a denser shrub you can cut back the stems but it is not absolutely necessary.....the plant should generate some new growth from the root crown each season anyway. And there is some validity to the argument that allowing the stems to remain intact so that the wood has time to 'ripen' will provide better support for heavy flowerheads and the plant will not droop from their weight. Any pruning on paniculatas should be done in late winter or early spring as new growth emerges - it will have no effect on flower production.

Thank you gardengal48 I was hoping I wouldnt have to prune them. Cant wait til next spring, they are gorgeous now so I can just image how great they will look next year.