Oh, wow. It is going to be very unhappy. The high of the day, temperature-wise, is going to occur just as it is time to start getting direct sun! Can you block the 5pm sun with another plant such that it gets dappled sun only instead... from now on? In the mean time, you could use an umbrella to temporarily provide shade at and after 5pm. The leaves will lose moisture quite fast, such that the roots will have difficulty replacing it and then you get wilting. A windy location would make things worse as the leaves would dry out more easily due to high temperatures and drying winds. As the problem continues, the leaf edges may brown out inwards. Mulching (3-4" past the drip line) can help reduce soil moisture loss but not as much loss as the leaves will be losing so there will still be a net reduction in internal moisture. You can try watering the soil only and more than before, such that the soil is always damp/moist at all times during the summer, making it easy for the roots to absorb more water. Hard to say if roots were disturbed by the transplant too but that, of course, would not be good. You could also consider watering twice a day if the soil is not clay and it drains very well; the second time, I would water a tad, enough to get the top 4" wet only but, only if you see wilting. That is in order to avoid causing root rot. Finally, you could cut off the blooms as they require water as that water would be better used in the leaves and stems; if you do decide to deadhead early, cut the blooms at the peduncle, the string that attaches each bloom to the stem/branch. Note: also check for insufficient water: if it is getting enough water, you should feel the soil as moist/damp at a depth of 6-8" after the water has percolated and you then insert a finger. If the soil feels dry, either you missed a spot or did not use enough water. If it feels soggy/wet, better to skip watering at that time.

Rather than move it in mid summer I think I would have accepted the damage on the assumption that an established shrub would recover better from broken branches than from root disturbance.

@floral_uk z.8/9 SW UK, in this case the roots of the tree went right under it, too. So when he levels the land and pushes off the stumps, it was gonna get pulled up anyway.

@luis_pr, the soil it's in is really 20 years of decomposed mulch, so it's fast draining but naturally pretty dry. Do you think I should move it to a different area that's nothing but dappled sun, but a lot more moist? Rhodos, azaleas, and hostas are doing really well in that second area.

“Do you think I should move it to a different area that's nothing but dappled sun, but a lot more moist? Rhodos, azaleas, and hostas are doing really well in that second area.”

That different area souns like it has a better track record so yes. Try not to disturb the roots as best as you can.

This was taken yesterday at 2pm, before I cut off the blooms:

It looks even worse today, so I'm gonna move it.

I thought about moving it to a large pot with potting soil, but then I read that nitrogen isn't good for it right now and all I have is Miracle Gro potting soil that's 21-11-16.

I have rhodo / azalea food that's 30-30-10 (high nitrogen but also high phosphorus), do you think that would help?

The soil does not look too-too damp/mist in the picture. The corner spot may be windy, which helps dehydrate the leaves fast. Temperatures much above 85F will also promote wilting all by themselves but if the soil remains damp, the leaves will be fine as soon as temperatures recede and come below 85F. Normal behavior for newly planted hydrangeas whose root system is still small. Not sure how wise this variety gets but it seems planted too close to the house for a 4 or 6 wide specimen; ok for smaller specimens. Check the soil pH near the house sporadically as cement tends to release lime and make things alkaline on new houses.

I thought this would be a good spot because it's similar to the original location (which was close to a fence on the north side) but with less sun. I actually thought that the lesser sunlight would be the biggest issue! LOL

Great point about the cement foundation, though! I have a Japanese maple near the foundation in full sun, and a few years ago someone on here (@ken_adrian Adrian MI cold Z5, I think) suggested the same issue and recommended more or less flooding it with a garden house to wash the lime from the roots. I did that, and the tree is gorgeous this year!

Either way, it's moved now to a dappled-sun-only area with a fence on the east, north, and west that stays a lot more moist. I gave it 2G of water, and there's an impact sprinkler that I've set to run every morning at 7am. I'll might water it manually at around 2pm, too.

I'll post back in a few days with an update!

keep it properly watered .. and nurse it along until fall.. IF it should live.. and then move it to a spot that isnt literally inches form the house ..

when you do stuff like this.. wildly out of season .. its best to pot the stuff in good media .. and place in full shade.. and keep very damp ..

instead of keeping ma nature in the equation ...

and other than watering.. stop thinking or worrying about it.. whats the use.. its going to take weeks if not months to recover .. so why fixate on it every day ...

you do what you have to do.. when you have to do it.. and then wing it .. but dont worry about it ..

ken

ps: its severely and extremely stressed.. IT IS NOT HUNGRY.. fert is not a response to stress.. EVER..never..never..never ...

and other than watering.. stop thinking or worrying about it.. whats the use.. its going to take weeks if not months to recover .. so why fixate on it every day ...

@ken_adrian Adrian MI cold Z5, I have a super stressful job, so I spend a few hours working in my gardens every day to get away from it :-) I'm already hand-watering my peppers and tomatoes, so it's not a problem to pet this one a little, too.

ps: its severely and extremely stressed.. IT IS NOT HUNGRY.. fert is not a response to stress.. EVER..never..never..never ...

That theory came from:

"The more phosphorus a hydrangea gets, the more powerful its root system will be. It is best if you use a slow-release fertilizer with a high phosphorus content. Hydrangeas will then get all the elements in the right amounts and regularly.

This also means you need to avoid nitrogen-rich fertilizers. Otherwise, this will cause rapid growth of leaves which might wilt."

https://worldofgardenplants.com/hydrangea-transplant-shock/

I don't know the actual phosphorus content of the soil, but since rhodos and azaleas have done well in this new area then I'm hoping it's a better location. It looks about the same today as it did yesterday, so fingers crossed!

Water it more that you think it needs. A Hydrangea uprooted and moved in full growth is effectively like a cut flower in a vase. The roots will not be working yet so it needs to be absolutely drenched. And because the roots aren’t working fertilising is utterly pointless. Advice for established plants is not relevant for transplants, especially those done at the worst possible time.

I've been giving it 2 gallons, twice a day, plus whatever it's getting from the impact sprinkler. Today I saw a few leaves starting to perk up, so that's promising :-D

I was really surprised that it went in to shock, I dug up an area about 3' wide and didn't see any root exposed! It was a lot more sensitive than I thought, so if it survives I'm nervous about moving it again. Maybe in November? Or next November?

Wanted to give you all an update, it looks like it's bouncing back pretty well :-) There are still some wilty leaves, but nothing like before.

I have some leaves that are obviously show, like this:

Should I cut them off but leave the wimpy stem? Or cut off the wimpy stem, too? Or just let it simmer and take care of itself?