It is very difficult to tell. Last year, I had a hydrangea that suffered thru the exceptional drought and three months of 100 degree weather. I was concerned because the soil was kept evenly moist and yet all leaves browned out. Then a handful of leaves popped up in September and it is back now as if nothing had happened. To declare it a goner, I would wait until leaf out time in Spring 2013. In the meantime, maintained them well mulched (3-4" thru the drip line), keep the soil as evenly moist as you can and put some shade protection (shade cloth 35%) if you wish.

Good advice from Luis. Just want to point out that my Nikko Blue could not take much sun at all. Kept growing on the side that was in shade most of the time and kept receding back on the side that got considerable sun. Over time, Nikko Blue moved itself about a foot over in the mostly shady area.

To me, that means Nikko Blue likes shade, not sun.

Kate

Especially in these droughts hydrangeas can look fine one minute and terrible the next. Bottom line is, even long-established plants are beginning to droop badly now which means they are in severe need of water. Shade will keep the plants and soil from drying out as quickly, but stuff in shade can end up as dry as anywhere else!

I agree with Dublinbay and what you said about moving it to partial sun.

I put in two new Nikko's this spring. They get direct full sun until 1230 or so and then shade the rest of the day. They seem to really love this as it was packed with blooms and new branches are still growing. Even in this crazy heat I only water deeply about every other day and it hasn't drooped on me yet. Full sun I think is def too much for a Nikko without having to baby it non-stop.

Thanks for all the help -- they've perked up a bit -- thinking I can wait till fall until transplanting but am considering an emergency/mid -summer move .. Any thoughts?

If you are out there watering a ton and its still looking rough you are better off moving it now. I only say this because I am assuming these Nikkos are fairly new and dont have their roots well established yet. Sure its not ideal but sometimes ideal doesn't work for everyone. If possible wait till you see a forecast of a day or 2 of rain/cloudy skys as opposed to a day of high heat. However if they are a couple years old I would just wait till the fall.

I've had to move plants mid summer before for similar situations and although takes some more babying for about a week they end up doing better if their new location is more suited to the plant.

I would say hold off on moving them now. Instead put up a shade cloth or use some nettings to provide temporary shade set up on bamboo poles. I had to do this to new my nikko blues before when they got fried after just been planted out. After a while they did recover and grew well since. They do like light shade condition.

Wait til fall to move them. By then, the plants will start going dormant and there would be less chances for root damage.