I have alot of hydrangeas also and find sometimes its not from to little or to much water but inconsistant water. Like indoor plants when their tips turn brown thats usually from to long between watering. We just went through a few weeks of little or no water. Hydrangeas are pretty tough and I doubt that they are seriously damaged....bobby

Hydrangeas (not the oakleaf type) can get some diseases. I have a friend with a lawn and landscape business and she said that they have noted that the disease seems worse the last few years, probably because of drought.

GGG

Here is a link I found via google, that has a lot of good info.

http://www.aces.edu/pubs/docs/A/ANR-1212/ANR-1212.pdf

I have 6 hydrageas in big planters that are in full sun..no shade trees. Some of the blooms are getting brown . They are watered 3 times a day for a minute due to the constant sun on them. They only have shaded sun if there are clouds. I am wondering if it is too much water or not. When the hot sun has been on them for hours they are definitely wilted and perk up when the sprinklers go on.