Hello, no-green-thumb. Some of the varieties of potted hydrangeas sold in grocery stores and florists do not do well in cold zones. Varieties that do well are the Endless Summer Series, Forever and Ever Series, etc. There is a very good chance that this one is not good in Zone 5. The ones that do tend to be named cultivars that bloom on new wood and grocery store plants generally do not include ES's and such. But they can be awesome looking. I visited a relative in SC some years ago and was blown away by some of the ones I saw for sale at a grocery store (always with a plain ole label saying "hydrangea" and nothing else. Oh well.

If your plant would have come with a plant label, that would have been great since the label can tell you if it is good in your zone. Since it did not, I would plant it now in order for it to get acclimated to your garden a.s.a.p and I would winter protect it heavily every year.

If it does not come back, it just could not handle your cold winters. If it comes back from the crown and all the stems are dried out by the end of May then you may get a nice green bush with no flowers. At this point, you could try an even more stronger dosage of winter protection but if it continues doing that on years 2-3, I would replace it.

Another alternative would be to keep it in a potted container, where you will have to pay attention to soil moisture, especially during the hot summer months when very frequent waterings are needed on most potted shrubs. Fertilize it monthly with a slow-release general purpose fertilizer, mulch it and add some amendments to lower the pH now and then. Oh, you will have to bring it inside when it goes dormant in Fall and bring it outside when temperatures warm in Spring (usually 2 weeks after your avge date of last frost). Change the potting medium every 3-4 years and tweak the container size as needed.

Does that help you?
Luis

Luis,
Yes, this does help me. Thank you. I am thinking I may try to keep it in a container and just bring it in for the winter. My sunroom is at about 55 degrees in the winter unless we are using the pot belly stove in it - so that might be a good place to keep it???
Can I expect these blooms to last for a long time?
I love the way it looks on my patio table!!
Thank you again for your help.