Hello gamrenee1. I assume your hydrangea is a mophead or lacecap. And the answer to the subject line is no, the root system was not affected but the part of the plant above the ground was damaged somewhat. It will recover.

Some of those stems may generate new leaf buds but it will be difficult to predict the final outcome. Ditto for the flower buds. I would expect that if the leaves got hit, then flower buds got hit as well and the question is whether either will come back. New leaves will develop from sticks that survived and -you already know- from new stems that the plant is developing already from the crown.

The variety of hydrangea is important in deciding what will happen next.

If the variety that you have blooms on old wood only, it will develop flower buds for Spring 2011 this Fall. Not likely it will have any blooms this year if the damage killed all the flower buds. If it is a remontant variety like Endless Summer, it will not bloom early this Spring but it will develop new flower buds later on and these will open and bloom as usual, just a little later than normal.

You can leave the sticks around a little longer; if they are still green, they may still leaf out. Wait until early June. Then prune the sticks in 1 or 2" increments until you get to the bottom or until you "hit" green.

Good luck,
Luis