I apologize for the delay in responding to your request. 

It's very likely that the plants ran short of water because they were in pots.  If you already planted them in the garden, know that the most important place to water for the first few weeks is the area of the original rootball.

If the hydrangea is still alive but looking puny, cut off all the flowers.  Even though that sounds drastic, doing so will make it easier for the root system to supply water to the top growth.

If the above information misses the point, please reply to this email to tell me what you have done and how the plants have responded. Also attach additional images if you think that will help explain the situation.