What does a frost crack look like?

Q. I’ve heard about trees developing frost cracks in winter. How can I tell if any of my trees have a frost crack? What does a frost crack look like?

A. Early this spring, walk around your property and examine your trees. If you see any significant vertical cracks, they are most likely frost cracks.

The tree will grow over the crack with “reaction wood” in spring and summer. This makes it more difficult to identify frost crack damage later in the year.

Frost cracks can damage and kill the bark and cambium layer, so also look for a long, vertical sunken wound on the trunk.

In some cases, however, frost cracks are only internal; because they form below the surface of the bark, you may not be able to detect them for a year or two.