Hello, kenflzone9. I would not worry about the look of the leaves in winter. If our own skin was allowed to be exposed to the sun, rain, snow, ice, dust storms etc throughout the growing season, I am sure we would be looking pitiful too. The leaves will usually shrivel and fall down on their own as winter progresses but sometimes not in mild winter areas. I ignore the leaves and the flowers if they look like that & let them fall when the plant chooses.

The grayish colors that you notice are probably signs of powdery mildew. Many hydrangeas suffer from this. Old fungal infections from the Fall may have been invisible months ago but can turn out more visible as the leaves fade in late Fall and Winter. You can get rid of the ugly leaves now as the shrub begins to leaf out or not (I would personally just leave them though). Just cut the leaf node only so the rest of the stem and any flower buds are not affected.

Make a habit of watering the soil early in the mornings around the base of the plant, instead of watering the leaves. This minimizes the chance of fungal diseases like powdery mildew. You can also keep the base of the plant tidy and clean with no plant debris. Maintain 3-4" of mulch at all times (check & add in Spring/Fall) and water when a finger inserted to a depth of 4" feels almost dry or dry. Do not plant the shrub close to others in order to allow air movement as this helps evaporate water on the leaves.

The plant is going thru some transplant shock now so the best you can do is give it TLC. Maintain the soil constantly moist (as best as you can) and keep the plant well mulched. This is easy to do now but, keep an eye on the soil moisture during the summer.

Unless your soil is deficient in minerals, I would consider not fertilizing it this year or fertilizing it less (say half what you normally use). If you wish to add some fertilizers, use weak ones like liquid seaweed or liquid fish. You can prune off any dead and dry stems by the end of June. In July, the shrub will begin to develop flower buds so do not prune it in July or later. Next year, you can fertilize with some cottonseed meal, composted manure or a general-purpose chemical fertilizer like Osmocote (per label directions) in early May and July.

To determine its watering regimen, use the finger method. Check the soil daily for 2-3 weeks and water only when the soil feels almost dry. Each time that you water, make a note on a wall calendar. After 2-3 weeks, review the information on the wall calendar and determine how often you had to water (once a week, twice a week, etc). Then set the sprinkler on that frequency. About 1g of water is good on 1-5g potted plants but I am not sure on yours. You can play it by ear. Use the finger method when the temperatures change by 10-15 degrees and stay there.

If your soil is not acidic, purchase a soil pH Kit to keep an eye on the acidity and apply amendments as needed. Aluminum sulfate is good when your soil lacks naturally occurring aluminum. Soil Sulphur is also good when your soil has aluminum. Now is a good time to add amendments in alkaline soils. I also have add more by July or in September.

I hope that helps. Good luck, kenflzone9.
Luis