Polar vortex blues

Hey all,

I planted about 60 fruit trees last spring here in Ohio zone 6a. All the trees are compatible for zone 6, and about half are even zone 4/5.  They were all heavily manured and mulched and there is about 6" of snow on the ground. I did not cover them or provide any wind break and now am freaked out that this crazy polar vortex cold snap of negative farenheigt with kill them all.  I know the horse is already out of the barn, but is there anything that can be done post-fact?


I am also somewhat confused how tree coverings actually help with this. Wind chill is a means of expressing rate of cooling that incorporates convection, but how is this relevant to trees that are not warm bodies and are essentially the same temperature as the atmosphere. There is no additional 'warmth' provided by them.

Zone 4 is down to -30F, zone 5 to -20F and zone 6 to -10F.  As long as you keep your trees at or above -10F you should be fine with all of them.  Below that and you could lose the higher zone trees.  Wind chill shouldn't make a huge difference, but shielding them from wind might help a little.

The other thing that might help you is that the "polar vortex" is supposed to only keep things super cold for a day or two.  If it was going to be that cold for weeks you'd be in much worse shape.  Just guessing, but you probably will have some branches that die and need to be trimmed, but hopefully you won't lose entire trees, depending on how cold it actually gets.

After it thaws, make sure the freezing and thawing didn’t push any roots out of the ground.

Just a reminder, because of the snap cold, you will lose some buds, especially if it was warm for a while before this snap (and it might not be the last of the year), BUT-- the bugs are going to get whacked hard too. So this spring is likely to be pretty low pathogenic insect pressure.

This also means the pollinators are going to need some extra help early in the spring. I put down crimson clover which is cheap and blooms pretty early (at least around here) and buckwheat also will pop up quickly.