'watering every day' sounds like you are watering too much. That may be causing yellow leaves if the roots cannot get oxygen or if they are heat stressed. Water them only if the soil feels dry or almost dry. You may also want to give them extra shade with a lawn chair or something, if you can. It is their first summer and they may pout. If they wilt, they should recover on their own by night time or next morning but that works only if the soil is moist. If not recovered by the next morning, water them.

Not sure if heavy blooms may be contributing to Bobo's flopping issues. Normal on new hydrangeas to bloom and cause some flopping. But it is just a guess as I cannot 'see' the shrubs.

Everyone! Stop stop stop watering your H paniculatas. No no no, don't don't don't, never never never, unless the stems and leaves are drooping for more than a day.

Oh come on!! You can't possibly make a statement like that!! When and how much to water depends on things we cannot possibly have any first-hand knowledge of - soil conditions and drainage, weather/natural precipitation, temperatures, siting (sun/shade?), how well/long the plant is established, if it is grown in the ground or in a container, etc., etc.

Depending on the situation, newly planted paniculatas may indeed require frequent watering, whereas established shrubs under different conditions may require very little.

One of the primary attributes of a 'good' gardener is knowing when and how much to water and that is not something somebody online or what you read in a book can tell you - it is entirely experiential!! And until you know your conditions and are used to growing the plant, testing the soil for moisture at the depth of the rootball is the only way to tell.

Also, planting anything in the middle of summer pretty much anywhere in North America leaves you open to transplant shock.......which can also account for yellow or drying foliage.

I think the transplant shock has a lot to do with this also. I really don't consider myself a "gardener" I just love flowers and wanted something new this year. The lady at the nursery sold me on the hydrangeas because I told her they would be in the sun 85% of the time. I showed her pics of my flower beds, etc. She should know what type of soil our area has right? I trusted her judgment... but I am a little worried that they won't "snap" out of it... I need to quit worrying I know. If I go a day without watering them all the leaves will droop. On a positive note, the white flowers look great so far! My new spilled wine Weigela also droops when I miss a day.

I have a new but un-planted yet mophead (not white) that gets sun from 11am-1pm approximately. It pouts when the strong summer sun hits it (meaning it wilts) but then it looks fine by 3-5pm, which actually caught me off guard. Quick recovery! I had been checking it late afternoon and noticing it was not wilting and thinking it was never wilted before that until.... I just happened to time one of my 'wilting checks' at lunch time. So it recovers quite nicely, which is great because I have been keeping the potting soil evenly moist.