My daughter bought a nursery 2 1/2 ft diameter hydrangea sitting in shade with others. I left it on my east deck overnight and next morn it was in full sun til that afternoon. The leaves wilted so I watered it. It perked up and then I moved it to my front roof covered porch on west side after talking with nursery owner. The next day black edges on the leaves began to appear. Now 7 days later, it doesn;t look like the gorgeous healthy plant we bought. It has many black edged curled leaves and limbs are bending over like wilted. He told me it could grow in the container in shady area. The porch gets sunshine after about 4-5 pm.It was in the car to come home only about 15 min.
Also one bloom is beginning to open and it is pink. He told me it was going to be blue. This is from a 40 year well established nursery
in our county. I suppose there will be no blue blooms this year. Actually it was Mother's Day gift from my daughter who is crazy about
anything blue and white. She will inherit the house and I wanted to begin to establish a blue hydrangea garden for her- her favorite flower.
I am aware of the soil content making blooms pink or blue. What I do for it from the present condition? Thanks for any advice. We wanted one for several years.

I have heard some people using epsom salt mixed in water to perk plants up. I don't know what to tell you about the leaves. Maybe post a picture so others can help

2GrammyGlow - To get the blue color, fertilize with aluminum sulfate.

Does it get very hot on the porch after 4-5 p.m.? I wonder if because it was in shade in the nursery it can't handle bright sun or heat until it adjusts. The late afternoon sun is going to be hotter and brighter than early morning sun. Was it in a greenhouse at the nursery, or outside? If the leaves got burnt by too much sudden sun those crispy edges won't recover even if the plant as a whole is OK. Is there any chance you could post a picture?

to NGA.

Glad to be here ! The afternoon sun on the porch is filtered by a row of tall pine trees. In the nursery it was outside under a netting ceiling with about 20 other hydrangeas. Does it take a year or another growing or blooming season for the blooms to become blue? I was wondering if the sudden sun is what hurt it. I assume those blackened leaves will all fall off. My experience has been with Christmas cactus, begonias indoors and azaleas and roses outside. Thank you for the help. So sorry I can't post pictures, need new camera right now.

@GrammyGlow - To get the blue color, fertilize with aluminum sulfate

The color will change as soon as you change the pH of the soil which will happen if you give it some acid fert like aluminum sulphate.

Hydrangeas like to grow in similar conditions to azaleas, acid soil, lots of humus, moisture and cool shade. Your plant may be distressed just because it is no longer surrounded by its friends - the other pots around it were probably keeping the roots cooler. Try giving it a cool drink with the hose in the heat of the afternoon.

Yes, I think the burnt leaves were from the sun exposure. They won't recover but as long as parts of them are green they're still working for your plant.