Are you sure all of your compost is finished? If it isn't, it may be tying up your Nitrogen. Maybe a little fish emulsion will perk them up.

First, let's start with the same suggestion that virtually every new poster to GW will engender - include your location and/or climate zone with every post OR change your profile to reflect it. You will get much faster and more complete answers that are appropriate to your specific location, if we know what it is. Second, with any plantings, you can't water to a specific schedule. The frequency of the need to water is dependent on soil conditions, siting and weather. When you do water you want to water thoroughly, so the water can percolate down through the soil profile the full depth of the rootball. Third, the hydrangeas appear to be planted in amongst a bunch of weeds or weedy grass. Why are they not in clear planting beds? Lawns, weed grasses and weeds can easily outcompete young, newly planted plants for both soil moisture and nutrients, delaying proper establishment. A defined, clear planting area surrounding the plants (or a single planting bed that contains them all) that is kept free of weeds and grass is preferred. And this should be mulched, both to keep any weeds down and to insulate the soil and prevent evaporation. The leaves of the plants don't look too bad - a little off color and a few showing scorched tips - but overall they look as though the plants are receiving adequate water. The browned or withered flowers are just flowers that have passed their prime. They can be removed to improve the plants' appearance. Depending on the type of hydrangeas they are (another useful piece of info we lack), they may not produce any more flowers this season. Hydrangea macrophyllas that bloom on old wood (the vast majority of them) create flower buds in late summer or fall of the previous year. Once those buds have bloomed, that's it for the year. Reblooming macs (those that bloom on both old and new growth) can generate additional flower buds in season but young, new plants like these are not so much inclined to do so until fully established. The offcolor of the foliage and the faded flowers could indicate these plants are receiving a bit more sun than they'd prefer. This is not a deal breaker but something to be aware of and to work to offset. Or you could relocate these plants in fall to a shadier location (morning sun only) and plant more sun tolerant panicle hydrangeas (Hydrangea paniculata cultivars) in their place.

I mentioned it in another thread, but it bares repeating~two, three year old Crepe Myrtles, approximately 8' tall x 6' wide died over the last couple of months. I didn't do anything differently this year than I did last year, and the heat was just as intense. In the last 2 years, i've also lost 4 trees, two had rotted from the inside, a third went from green to brown, and the fourth kept leaning in every direction as I kept restaking it. and it AND I, finally gave up, after one of the many rain storms took it to the ground. It was as though the root system came detached from the soil. The only thing hanging on are the five Crepe Myrtle trees which were put in at the same time as the Wax Myrtles, and I should probably be knocking on wood! I keep thinking not enough of the caliche was removed and enough good soil added. I'm afraid to replant anything, but I would like trees in my backyard! The builder planted an assortment of bushes in the front yard, and in the seven years i've been in the house, none have died. The bushes haven't grown huge, so I think they may all be dwarf varieties, which leads me to believe the root system isn't as deep, reaching to the caliche. Does any of this make sense?

Definitely pinch anything yellow off. You could try watering less. Just keep an eye on it and make adjustments as needed. Is there proper drainage material in the base of the pot? Is the pot sitting directly on the ground? If you can, raise the base off the ground with some pot feet or blocks so the pot may drain freely.