I have (easily?) overwintered, outdoors, a potted paniculata for 3 successive winters (CDN zone 6). You are in a more moderate zone than I but your pots are much smaller than the one I am using. How about trying both ways that you have described ie some between the hedges and some under the deck?

Any leftovers that I need to overwinter in pots get sunk into the ground around here.

We just dig a hole, "plant" the pots, and toss some mulch on top- the ground does all the insulating they need. In spring they're super easy to lift and do whatever with.

I am in the Atlanta area and it was zone 7 years ago (maybe 8 today?) and I have many hydrangeas in pots for years with no extra work to winter protect them. They would probably do better in the ground but in pots I can move them about and keep them happy until I find a good permanent spot for them. Tree root competition was a problem for a lot of them so I dug them up and put them in pots to keep them going.

Like cearbhaill has mentioned you can bury them in mulch. The term is called "heeling" when you do this

Thank you for the suggestions. I know that sinking the pots in the ground would work, but given that I will probably have like 80-100, it's just not feasible. The Hydrangeas in the smaller pots will be transferred into 3 gallon containers.

I'll try to remember to update this thread next spring with the results.

Im in 7b. I have a paniculata that i do nothing special to protect that comes back fabulously every year. i have a mac that Ive done various things to over the years. Last year I moved it close to the house and merely covered it during the truly cold snaps starting in March. best year ever. note these are established potted bushes.

Jana, thats crazy you are in the same zone(7B) as me and im in north georgia,near chattanooga. Is that right? I know you guys have a lot colder winters than us. We got about 1 inch of snow last winter. I know you had alot more than that??

Randy Man,

I think the experts have changed zones on us a few years ago. I'm in Atlanta and it was always zone 7 for decades. I questioned how somebody in NJ or NYC could be the same zone as us. We are now zone 8. Here is a climate map from 2005 and I haven't seen single digits in many years in our area. Even the teens are hard to remember in the last few years. Climate change is real for better or worse. If this continues we will be zone 9 in another 10 years or less if the trends continue.

https://www.gardeningknowhow.com/planting-zones/georgia-planting-zones.htm

I probably should have been more specific when I said Zone 7 - I'm in NY (Long Island) and we do encounter some tough winters. I would say they're similar to what you experience in Philadelphia, but significantly colder than Georgia.

Philly, which is between two rivers, officially is 7a, but I live in the city and my concrete fenced backyard is small, 16x20. I've determined I'm closer to 7b. My roses start leafing out in early March. With my mac, I start paying really close to attention to cold snaps starting in March, but i dont protect my other numerous potted perenials.

So @zooba72 what happened?