Here’s an example of a tree that had zero protection other than wood chips being mounded up just above the graft. This is “Jade” grafted on a Bacon seedling, which has regrown nicely and doesn’t seem interested in slowing any time soon:
There was some freeze damage to the trunk above and below the graft union, but that seems to be healing:
Last fall it kept growing until a freeze in November (two consecutive nights around 28°F) killed most of the unhardened leaves. It was otherwise basically unbothered by a few similar freezes until the bad one in January. This is what it looked like just before the January freeze:
And this is what it looked like in the middle of the freeze, showing what protection it got:
