Susan,

This time of year, the previously green stems are aging into old wood and that starts from the bottom and works it's way up the stem. No problem there unless the stems are turning brittle and or hollow. It's also getting to be that time of year when leaves will start a downward trend on their way to dormancy and dryness will accelerate that process. My leaves have already degenerated somewhat and because of my zone's extended season, many of my hydrangeas have replaced the old ones with new sets of leaves. (almost like another Spring). Hope this helps to ease your mind......yg

Hi Susan- I am having the same problem up here in New England. I've had hygrangeas for years and have never seen anything like this. The leaves began getting brown on one end and the brown grew and grew.... and now entire stems are bare. I hope someone else out there has seen this problem and can give us a clue. I only wish my problem was what Yellow Girl described! That would be a blessing. Anyone out there with a solution? TIA.
-Donna

I peraonlly have no clue. However, thought this link might help.

Here is a link that might be useful: Disesase of hydrangea