The problem is that here in No. Va., at least, it's two to three weeks too early for this depth and duration of cold weather. The lows at night for the next few days are forecast to be in the mid-20s-below freezing. Daytime highs will struggle to get out of the 30's today. The cold's grip will loosen a bit, but below freezing temps remain in the forecast through Saturday night.
The issue is that it was 100 degrees a month ago. We've had NO significant frost/shallow freezes to date. Most of my trees are juust beginning to enter dormancy. Such a prolonged period of deep cold will prevent soil in pots on benches from thawing during the day. With no real pause in the daytime to thaw, roots will remain frozen and potentially be damaged as they haven't had a gradual decline in temps to adequately harden off. Sudden drops like this are not good. Mulching trees on the ground is a good thing to do at this point, as it lags temperatures and the mulch pile warms in sunlight. Mulch piles should be deep and BIG if you can make them that way, as more mass holds onto relative warmth from the ground and from sunshine.
I've only brought a couple of trees inside that I normally store in a cold greenhouse elsewhere. I plan on bringing them back out once the temps reliably rise above 30 F at night.
BTW, this kind of thing is why you have to keep a close eye on weather forecasts. This cold trough of air has been in the forecast for more than a week. Not shaking a finger at anyone in particular ;-), but winter prep isn't something you can schedule. It relies on the weather which has been pretty unpredictable in the last couple of months.
