The first year will be hard, especially in this heat. Wherever you move them, they are going to need help through this first season. Until the become established I will let the hose drip around one all day while I'm at work. The next day I let it drip around another one. Even my well established plants wilt some. I just water them well in the evening, about every-other-day. It has been about 10 days since we've had significant rain so they are showing signs of stress. Your new plants will need TLC. It isn't so much the heat as it is the moisture.

I can't speak for those varieties but I planted an Endless Summer a couple of years ago that was getting too much sun. I decided to move it that fall and it now gets about 5-6 hours of morning sun and shade all afternoon. It's bloomed beautifully this summer. As far south as you are I would recommend afternoon shade if at all possible.

As was said before, newly planted hydrangeas are thirsty, thirsty, thirsty and it sounds like you have had some HOT weather. How about you try the Miracle-Gro Moisture Max soil + more mulch? You will see an improvement and you will see a dramatic improvement next year as the hydrangeas' roots establish themselves. I grow several macrophyllas in full sun and trust me, it gets hot here in Ohio. The first year, everytime, I am thinking "hmm, maybe I should move this guy" and then by the next summer, the plant is well adjusted. Good luck! I got a kick out of your "This is my first try at starting a collection of specific hydrangeas vs. just going down to Home Depot and buying the first one I see." It takes a special person not to do that!

Hydrangea729, you've responded to a 3 year old post.

Thanks hydrangea729, it is the answer I was looking for! 3 days ago I transplanted a nikko mophead. Every day by 6 pm, it looks pretty wimpy. It gets at least 2-3 hours of afternoon sun. I was tempted to try another location (but this where I really want it to stay) instead I am going to try to Moisture max soil and mulch and every other day watering.