Need lend a hand next to Hydrangea bush? Should you cut back a hydrangea bush within the Winter? And...

Should you cut back a hydrangea bush within the Winter? And if it's cut back (almost to the ground), will it come subsidise in the Spring?
Mopheads and many big-leaf hydrangeas (H. macrophylla) bloom on outmoded wood, so any late-season (or fall or winter) pruning you do erases subsequent year's flowers.

The smooth hydrangea (Hydrangea arborescens), bloom on new wood so pruning those surrounded by late winter or rash spring wouldn't be a problem.

'Endless Summer' is type of mophead hydrangea that will bloom no matter when they are pruned, & will regenerate the bloom bud even if the spring frost destroyed its aged blooms.

If you're not sure what kind of Hydrangea you hold, wait & prune it right after it blooms.

http://gardening.about.com/od/treesshrub...
http://www.yourgarden.com/qa/eng/special...

P.S. You're plant isn't ruined. It'll grow, but might not flower this year if it as a rule blooms on old wood.

Good Luck! Hope this is of use.
You need to know what type you enjoy. Here is a very virtuous site:

http://www.hydrangeashydrangeas.com/faq....
Answers:    Yes you can cut it spinal column hard, also verbs in some ericaceous soil if you want the flowers to be blue, otherwise mundane soil for pink.
Most will not bloom if cut back, it will live but steal two years to bloom