Another image:

Looks like they need the soil amended to make it more acidic. Some leaves look a little chlorotic (common when using some types of rocks as mulch instead of regular organic mulch). Other leaves look like they could be turning yellow as many do in the Fall, just as the plants go dormant.You can confirm acidity issues by testing the soil pH with one of those test kits available at many plant nurseries. Normal soil pH should be acidic, less than 7.0. You can amend the soil to acidify it with greensand, aluminum sulfate, iron sulfate and many liquid compounds. The liquids correct the problem faster but they have to be applied more often. Fixing the problem depends how alkaline the soil level is but it usually takes a few weeks.

Some brown areas could be caused by soil moisture problems (not enough water or periods of dry-wet-dry soil); this problem makes the leaves turn brown from the edges inwards.

If the leaves were to turn this yellowish in the summer, I would consider adding some shade but, all things being equal, your sun in MN should be weak and not cause sunscorch like it happens down here. Rocks and some wall surfaces, however, could reflect the sun and cause too much sun issues.

I, too am having hydrangea issues that look like those posted above (great photos, btw rambler1963).

luis_pr, your descriptions, possible diagnosis and suggestions were very helpful to me and I hope were to rambler, as well. Thanks. annie

yw

If Annabelle looked like this all summer, you have a problem, but if it only started looking like this recently, it's just what happens as days shorten and temperatures cool at this time of year. IME Annabelle grows best with even moisture, organic mulch such as shredded bark (which helps with moisture) rather than rocks , and morning only sun. Annabelle can definitely get to looking scorched this far north if it has all day or all afternoon sun since the leaves transpire (give off moisture) faster than it can be replaced in hot sun.