I'm baffled why your shrubs would be wilting. That's the same kind in the pic below. I've made about a dozen babies from ground layering the mama shrubs and none of them ever wilt when separated from the mama & planted elsewhere, unless it doesn't rain for about a week. After a winter has passed, they don't need to be watered at all. Hot & muggy is the milieu of Hydrangeas.
Here's the temps here so far for June:
http://www.weather.com/weather...
Normally I wouldn't be surprised by faux wilt in the afternoon, a common occurrence for a lot of plants, but for a Hydrangea on the east side of the house, it's daggone strange.
Maybe a pic could help folks decipher the problem?