If the leaves are turning brown from the edges inwards, it may be having trouble with soil moisture. If the edges are browining but just a little and not the whole leaf turns brown, just near the edges, it may have an aphid infestation.

Because they are new, they may suffer unusually on this first summer. Think transplant shock. Their root system got pruned so the plant could fit in the pot, so it may not get as much moisture as it needs even when the soil is moist.

If the plant is not getting enough moisture, one of the first things to go will be bloomage. Then the leaves brown out if leaf wilting does not help.

If they are getting protection from the afternoon sun, I would temporarily try to give them additional shade somehow. The changeover from a nursery setting to the harsh summer sun may have been unusually hard.

I usually try to provide shade by 11am to 12pm over here. Dappled sun will also work fine.

Thanks, Luis! The sun on them isn't as strong in the afternoon as the morning, but it's still significant. If their location is a place with too much afternoon sun, would it be better to move them, or might they adapt over time?

The soil does stay moist, but it sounds like they still might not be getting enough moisture as you said. Any suggestions? Also any suggestions on varieties that thrive in nearly full hot sun?

Also, is the fact that the blooms on the back of the plant that is hidden from the sun are healthy, lush and a deep purple and the ones on the front that get sun are faded and more dry a sign that this is a sun issue and not a moisture issue? The only leaves that are turning brown on the edges get strong sun, the leaves on the back and inside of the plant are all green and look great.

It is normally not good to keep a shrub stressed for long periods of time so I would find another location or figure out a way to give them afternoon shade.

In time, their root system will develop and grow; it will be able to absorb more moisture from the soil but it will still stress out during the summer months. Maybe even develop sunscald later on. And future growth that grows into sunlight areas would be affected as well.

If you want something that will thrive in full sun (defined as more than 4 hours of sun), I would look for something like daylilies, roses, asters, black-eyed susan, phlox, salvia, etc

At this time, the plant is not adapted to being out in the garden summer conditions so both sun and moisture are a problem. I lean for moisture being slightly more of a problem with 'too much sun' not too far behind.

Too much sun exposure harms the leaves in direct contact with the sun and makes them turn all yellowish or white-ish, including the leaf veins. The fact sunscald has not happened (yet) suggests it is more of a moisture issue to me. But too much sun can still be a problem: it helps the moisture escape thru the leaves fast, which stresses the plant and does not allow it to thrive.

Just remember that hydrangeas developed in areas where they lived under trees, in locations where they do not get a lot of sun exposure, especially afternoon sun. Morning sun is less strong than afternoon sun so east facing locations are normally preferred. The more you can provide those conditions, the easier the plant will adapt to your garden.

Thanks very much! That is very helpful. They are in an Eastern facing location currently. Perhaps I should try to provide temporary shade and see if they improve. I want to give them a chance, but also don't want to put them through too much in trying to do so. What are some good ways to provide temporary shade for the hot summer months?

I once had to rig up a contraption because one of my hydrangeas got exposed to too much sun and suffered from sunscald weeks after a hail storm pruned the tree that was shading it. My first esposure to the problem. It took me a while to notice the problem because the plant is not in my direct line of sight when walking in that area so it finally developed sunscald on the leaves with direct contact with the sun. Quite odd looking. I thought it was niotrogen defficiency but then noticed that the leaves in direct contact with the sun were the only ones affected. That was the AHA! Moment.

I literally used sticks to prop up a piece of cardboard a foot above the shrub. Gosh, I had to fix it several times because it was so rinky dinky but it helped the shrub and I discarded it once the temps moderated in the Fall.

Nowadays, I would have gone shopping for some of the shade cloth that plant nurseries use, sometimes referred to as 35% shade cloth. There may be many places where you can find it on the Internet. I remember looking for it about 1 year ago when someone told me but I know do not remember the websites that I ended going to. Perhaps something with the word landscaping. But I remember thinking "what about calling a landscape company" if the plant nurseries did not carry shade cloth for sale to customers.

I'm growing Hydrangeas in shade ( Inland Orange County).