I know a guy in Alaska, he lays all the trees over on the ground, put some vole poison down, a tarp over and that's it.
I would be too worried in your room, heaving too much temperature fluctuation and mostly too warm.
It would be nice, if you can heal them into the dirt a little, at least halve of the pot, this is how I used to do it when
I sold trees in pots and had leftovers. Now I sell bare root only.
Water them in good before freeze up. I never lost any.

Konrad

Milehighgirl:

Agree with Konrad that your biggest problem in the upper room would be temperature fluctuation. During sunny days, the temperatures in an area like this would be quite high unless you were able to open it up to ventilation. Freezing in a protected room should not be an issue. Your trees might make it during several months of these conditions, but some of them might not. If you do decide to put them there, the pots should be watered just enough to keep them barely moist.

I would tend to go with Konrad's solution of heeling the plants into the ground, though that would be a lot of work with 40 large pots. You don't have too many good options, since you got a little ahead of the curve by purchasing trees before you were ready to plant.

Don Yellman, Great Falls, VA

Wow, I never thought about the temperature fluctuation! Would it be better to keep them in the garage where there are no windows and it's always cold?

I just don't see how I could manage heeling the pots in.

I did keep two mulberries in pots in the garage last winter. They were in very small pots as the trees were only about a foot tall. One made it fine and the other the root made it but not the graft; it sent up another shoot in the spring. I did not water them during the winter.

The trees are in 10 gallon pots or larger.

Thanks for your advice!

Milehigh:

Yes, it would be better to keep them in the garage, if temperatures are more constant, even if low. I think most of them would make it there, but check the moisture once in a while and do not allow them to become bone dry or the roots will die. Obviously, there will be no leaf transpiration to use up moisture, but there will be some evaporation from the pots. I would check them about every two weeks or so for soil moisture. My guess is that a 5-gallon bucket of water would not freeze solid in your garage, and neither will the soil in 10 gallon pots, which are quite large.

If you can't bury the pots or provide them with good insulation outdoors, your options are pretty limited, and this may be the best you can do.

Don Yellman, Great Falls, VA

I still think outside storing is better, plants are used to being outside, they love the snow and rain on the branches, it's part of
what they need, that's what keeps them alive, they are a outside species.
As soon you're taking this away, you're asking for trouble....the garage is too dry.

If you can't heel them in dirt, you could easily do it as Denninmi suggested, look for a sheltered spot, perhaps right against a wall of your
house, where snow drift's accumulate during winter, if not, rake some leaves or put straw over, or peat moss to cover your pots.

Konrad

Congrats on the getting the orchard going. Planting in pots is a great solution but you should keep them sheltered. Roots in ground don't feel -20 with snow cover. BR trees in pots outside would likely die some. Keep the pots watered, frozen is ok. Root growth will develop earlier than if planted outside. I'd seal the pruning cuts with latex paint to keep the stems from drying out. Now you have all winter to layout your orchard. I still have a few more large trees to take down before late March fruit tree planting. I just got finished fall planting seven blue berry's in a hedgerow after clearing trees.

I didn't have time to plant or heel in my roses and some blueberry bushes I had in rather small pots last year. Instead I put them in a large cluster and surrounded them with burlap and covered them with tons of leaves. Every one of them survived very well in SE Michigan where the temps often get below zero in the winter.

I had a peach tree in a container all last winter sitting in my garage. Moved it to the basement in the early spring and it started to leaf out! My garage is attached, but still gets very cold. Our low last winter was near -30F at one point. I'm guessing it probably goes below 0F even in that garage.

I have no experience with fruit trees in containers during winter time. something is telling me that peach trees would survive in containers inside some cold room? I keep fig trees in containers in cold room in my basement from early november until mid of march. i would make sure trees are well watered then i would put containers into garbage bags and tie up bags around tree trunk - loosely, and i leave it like that until spring time. Please people tell me how you do it. Thank you all

Keep the trees outdoors; the buds need the winter cold.

Set them side-by-side in a somewhat protected area.

Fill the spaces between the pots with mulch.

Mound more mulch above the pots, probably 6 inches or so.

Another method is to lay them down (as mentioned above), cover with mulch and then cover all with frost blanket, secured all around.

Check for specifics by talking with the folks at your county's Extension Service office.

Locate that office with this interactive map:

http://npic.orst.edu/pest/countyext.htm

I purchased 7 bareroot apples from Stark last summer during their sale. I planted them in pots and never got around to planting them in fall, so I overwintered them. I placed the pots as tight together as I could against the wall of my garage, but outside. Ideally I suppose I should have covered them with leaves and tried to get a tarp over them, but I was unable to do so. The only protection that they got was that I'd shovel snow over top of the pots every time that it snowed here, so they were under a pile of snow for at least 50% of the winter. I'm in zone 5A and they came out of the winter fine, are in the ground now and have broken dormancy and look fantastic. I'm not suggesting that trying to overwinter potted trees in cold areas is ideal, but if you have to do it and can give them any protection, they'll likely be OK. Admittedly, we had a fairly mild winter this year but were still sub-zero quite a few times.