Freeze damage to fruit tree roots sitting in pots above ground?

Hello,

I was wondering if anyone has any experience with having potted fruit trees being above ground in freezing temperatures?  At this time of year I always seem to have many plants in plants in pots which, because my summer plans went awry, didn't get planted as expected.   In the past I've always been able to, at least, get the pots buried in time to avoid freezing temperatures.

I got way behind this year for several reasons, and the weather (of course) has been below freezing several times in the morning.  This morning the low temp is hovering around 25 degrees F.  One morning last week I went out and was surprised to find the soil frozen in the pots frozen when the temperature was very close to 32 degrees.  It was only below 32 degrees for about two hours and I assumed that the pots would absorb enough heat from sitting on the ground that that they wouldn't freeze.  I was wrong.

I've moved the pots close to our house foundation, putting them close together, and covered them with a few leaves (couldn't find very many).  I've done some research and read that apple tree roots can withstand temperatures as low as 20 degrees.  

Would anyone have any practical experience with this to tell me if any harm has been done to my potted apple and pear trees yet?   I intend to get them either planted or buried soon, but I'm running out of time.  

Thank you for any advice or observations.  I really appreciate the advice that I get from you all.
Have a great day!
Tim

My potted fruit tree seedlings get frozen in their first winter above ground with some straw loosely piled around them. The pears did great and are now growing in the ground. Peaches did well too. I'm in zone 6a and the winters hit single digits for several days each winter, and occasionally sub-zero. I'm actually trying to weed out the weak seedlings before I go to the effort of planting them in the orchard.

I'd add a little more protection in the way of straw/hay or even an old bed sheet just to take the edge off the low temp spikes.

[quote=Robin Katz]My potted fruit tree seedlings get frozen in their first winter above ground with some straw loosely piled around them. The pears did great and are now growing in the ground. Peaches did well too. I'm in zone 6a and the winters hit single digits for several days each winter, and occasionally sub-zero. I'm actually trying to weed out the weak seedlings before I go to the effort of planting them in the orchard.

I'd add a little more protection in the way of straw/hay or even an old bed sheet just to take the edge off the low temp spikes.[/quote]

Thank you Robin

I really appreciate the information.....We're having awesome warm weather here for November in Central PA.  I'd really like to get everything planted, but I have such an unbelievable amount of work to finish up this year for some reason.  I might just end up mounding dirt around the plants against the foundation and hope for snow and a warm winter.  It would have been nice to get them in the ground...i just recently found out that the roots will grow and become established for a lot of the winter if planted now.


Thank you again!
Tim