Hello, rehabbingisgreen. The first one may be a hydrangea that is not winter hardy enough for your zone. The ones sold at grocery stores in foil wrap are a good example. Winter does not necessarily kill them but it dries out and-or freezes the stems, which kills the flower buds. All growth then comes back from the base when the plant starts growing again in the Spring. They do not rebloom so some form of winter protection techniques may help the buds & stems survive winter.

Placing chicken wire at least 6" away and 6" higher than the top stems in the Fall and filling the space with dried out leaves packed tight is one example. You can place the chicken wire early or mid Fall only and then fill them out later as they plant begins to go dormant or if you notice some really bad cold temperatures of 25 degrees or less approaching. A cardboard with some rocks can hold the leaves in place during winter and you can add more leaves in mid winter if you notice settling (keep the extra leaves in a plastic bag(s) for future use). Some people have also used hay instead of leaves, etc.

The F&E Series is a more winter hardy hydrangea. The flower buds that it develops now could still get killed, but it reblooms so you will get more flower buds in late Spring.

In the northern half of the country, hydrangeas can start to get more summer sun. If you have noticed that leaves are turning all yellow or white-ish, including the leaf veins, then the leaves need more shade. The best location for them would provide morning sun thru 11am-ish during the mid-to-late summer months. Two or more hours of sun is ok. Continuous sun is not necessary; you can select a place where they get dappled sun too. And you can also select places where they are in "bright shade" all the time.

Do not be afraid to try a spot. If you pick a spot and you see the leaves in direct contact with the sun turning all yellow -including the leaf veins- then transplant the shrub. This problem is bound to be detectable sometime around the months of June-August.

To get some ideas of "good places" you can look around the neighborhood for established hydrangeas. City and state gardens can also give you ideas. See how they planted theirs.

Does this help you, rehabbingisgreen?
Luis