Look up "hydrangea diseases" on the net. There is a sight that will go through just about all of the potential problems (with pictures)......yg

thanks. will do!

Well, the roots have been uncovered for a few days so maybe that's why they don't smell. But, I have to say they are a dark color and the plant doesn't have any of the spots associated with the other problems listed on the site. I think the medium it was planted in was too dense. I will probably go get some soil-less medium and try the replacement in a different pot. Then I will put something dispensable in this pot to test the dirt for the problematic nasties that cause roots to rot. I have extra impatiens with no home. If they die I will spread the dirt on the yard and bleach out the container. Both the containers used for this plant have been used often and I don't want to take any chances with another hydrangea. Especially since the poor Queen's Lace that I lost was in this one that this big leaf is now in. I will keep that site handy, yg. I appreciate the tip.

Ann, one good recommendation for containerized hydrangea is to put a gallon sized plant from the nursery directly into a 15 - 25 gal container containing a bark-based soilless compost. (of course, spread the roots by breaking up the rootball). Replace that potting medium with new every three years.

I would agree with morz8 regarding breaking up the rootball. It could have been that water wasn't penetrating deep inside the root mass.