where are you ...

in my MI ... i am not sure i would be repotting.. this time of year ...

we want plants slowing down and going dormant.. not getting all excited about new media.. and not going dormant .. what we might call.. not hardening off to winter temps ...

and my thoughts arent really BB related ... it would be a general rule for me.. in MI ...

this is the type of issue that is very zone dependent ...IMHO ...

ken

I plan to transplant three blueberry plants, but not until they are fully dormant. Also adding mulch in the soil is usually a bad idea. It uses nitrogen to break down and so the plant has less available nutrients. Using mulch as mulch is a really good idea. Wood on top usually doesn't pull nitrogen out of the soil. One mulch you can mix with soil is pine straw. It hardly uses any nitrogen to break down.

Thank you both. Drew how do you know when they are dorment? Do i have to transplant in the cold outside? Do I water outside in cold weather? How do I know when to stop watering? Do you think that I can repot in Spring? the bush was never repotted and I am afraid that it will out grow its current pot over the winter. Sorry about all the questions, first time.

I live in central PA

Even if it keeps it's leaves it should stop growing in the winter. As all plants do in temperate zones. You can repot it when it turns red. That's how you can tell if it keeps it's leaves. Otherwise wait till leaves are gone. Or you can wait till very late winter, or very early spring.before it starts growing. Yes, keep it just so slightly moist, if it dries out it could die. If it's too wet it could die. I would not leave it exposed to the elements. Overhead protection would be a good thing. Too much water and the roots will freeze solid. This is not that much of a concern, but if they thaw and freeze and thaw and freeze, etc, that is bad. In shade, with overhead protection. It's possible your pot may crack over winter. It's tough to winter in pots. It's super hard, the hardest way to overwinter anything is in pots outside.
If exposed to the elements they best be buried in the ground, the pot that is. leave one inch of lip of pot above ground. Bury in leaves, straw, or pine needles. This may not be needed, but if exposed completely it is needed.
You should never stop watering but probably only once a month to keep moist.

It's not that big a deal to transplant you could probably do it now. The suggestions I gave though are for best possible success. You can do it anytime. I myself would not do it before going dormant, it puts stress on the plant, and uses energy to repair damaged roots, when it should be shutting down for winter.