How do I winterize fruit trees for cold winters

Question

I have a few young fruit trees (1 each of a Liberty apple, Canadian Harmony peach, Bartlett pear, and Satsuma plum). I live in hardiness zone 5b in northern Utah, USA. The apple tree has survived a couple winters and the plum tree has survived one winter. This will be the first winter for the other 2 trees.

One thing that I've noticed is that the apple tree looks as if its bark is peeling (see below).

From what I've researched, this is due to freeze damage when the sap in the tree freezes and thaws during the winter months. I'm planning on wrapping my trees this year to prevent this on my other trees. However, I have a couple questions about winterizing trees:

1. Should I wrap all my trees every year, or is it not needed when they're more mature?
2. My trees are planted in my grass lawn. Do I need to add additional mulch for frost protection, or does the grass provide enough insulation?
3. Is there more I should be doing to overwinter my trees?

I still consider myself an amateur when it comes to trees, so any help would be appreciated so that I can give my fruit trees the best chance to thrive next year.

Answer 1

That's just normal apple tree getting older bark. It transitions from smooth to scaly with age, and is nothing to worry about. I don't see anything there that looks like typical "Southwest injury" damage.

Assuming your trees are not unsuitable for your climate, common winter preparations include things like providing a rodent guard (typically hardware cloth or spiral plastic) so the bark is not chewed off under the snow.

Pruning off any deadwood and removing that so it can't harbor pests overwintering is also typical.

If you have suburban deer (hoof-rats) you may need a different sort of guard to keep the deer from eating your trees, too.

Mulching around the trees (permanently) would be helpful, mostly because growing in full lawn tends to lead to trunk/bark damage from grass-mowing equipment, which can lead to disease/pest entry as well as simply being stressful injury.

Depending on your approach to gardening, you may also want to plant a ring of garlic around the trees, which is claimed to repel codling moths - and fall is the time to plant that.

Uncommon approaches I just can't get myself to commit to, for trees unsuited to the climate where you are, might include burying in fall and exhuming in spring (typical for fig trees. I like fresh figs. But not that much.)