i highly doubt there is frost heave in z7 in a greenhouse ... those roots appear to have been exposed a very long time ...

dampen some media.. and just lay it on top.. and walk away .. lets not kill them with too much love ...

i have seen many potted trees like this at production facilities.. and its not all that uncommon ..

ken

this is how heave works ... sure doesnt look like a few hours of cold in z7

You'll just have to wait and see.

I've wintered newly rooted cuttings of Tsuga canadensis in a cold frame where the temps got down to 20dF over a couple of months and had nothing bad happen.

Mine were in a 511 bark mix and when I brought them out in the spring, were thoroughly frozen like an ice cube.

I certainly would raise the soil level so it covers the roots. Roots drying would be as bad as getting too cold although 15d is pretty cold, so I would keep them a bit warmer for the rest of winter.

What you see is attributable to soil shrinkage (gassing off) or settling of the soil. It's no big deal. You can add additional soil to cover the roots (but not any of the stem/trunk) if you like, or leave it as it is.

Al

Thank you so much for the responses! I am still mulling what to do. There was **some** exposure of the roots even before this weekend, but the roots seem much more exposed now, and I am a little worried about damage either from dehydration or from the next cold snap.

My impression from what I've read is that the most I should do is mix up some moist medium to work gently under and around the roots so they are covered, but I am reluctant to do any more than that. Too much risk of killing them with love, as Ken says.

Unfortunately, there is nowhere warmer to put them. The house is warmer but way too dry.

I think the idea here is to keep them dormant until spring. Anything above low 40'sdf and they'll start to grow. I don't know when you want that to begin in z7.

Looking at your pictures, the cuttings look so nice and green (read healthy) so I wouldn't worry about them too much. You just don't want them to come out of dormancy, then go back into the deep freeze, at least not repeatedly. Most cold zone plants can take that to a certain extent.

Good luck and come back and let us know how things turn out. :-)

from what I've read is that the most I should do is mix up some moist medium to work gently under and around the roots so they are covered,

==>> no..no..no .. just apply topically to the proper height ...

this is not really any big deal at all.. every one of us told you that.. and you are still worrying ...

ken

i just noticed you have the pots wrapped in red bubble wrap .... lol ... why red??? ... not really necessary in your z7 for a plant winter hardy to z3 ... and in fact.. if it restricts FULL drainage.. could be a negative ....

anyway... when i was dabbling in growing trees in pots outside.. i found.. i was best off repotting EVERY spring ... and i also found that a media that was about half peat media and half mini chunks was just about perfect for the TOTAL absolute complete drainage ALL trees prefer when trapped in pots ...

i used about 50/50.. or you can invest in making al's famous 5-1-1 mix ... [what i made was very similar to orchid mix .... ]

anyway.. THAT is when you take care of this problem...NOT really in mid winter ...

ken

Ken, thanks for the follow-ups!

I ended up getting cold feet (hah), so I decided not to do anything for now. I'm too worried I will damage the roots by trying to fix something that is probably not a big problem.

I will wait until spring and then repot them as I had planned to do anyway. I think I am going to try the 5-1-1 mix.

And yes, I wrapped in bubble wrap to insulate them. Red was the cheapest color! Because of the shape of the pot, I don't think it restricts drainage. They seem to drain just fine.

Thanks again!