Frost cracks originate at a point where the trunk was physically injured in the past. Trees growing on poorly drained soils are particularly prone to frost cracks. Frost cracks often close during summer, only to re-open in succeeding winters. If cracks are only in the bark, they will not seriously damage it, although they do provide openings where certain disease organisms may enter the tree, particularly if the tree is in a weakened condition. Maples and sycamores are very prone to frost cracks while apples, ornamental crabapples, ash, beech, horse chestnut and tulip tree are susceptible.
Isolated trees are more subject to frost cracks than trees in groups or in forest settings.
In some cases when a scar or cavity forms, the wound will not heal properly at the edges. The wound tissue may roll inward as it grows, failing to close. This process will continue and outward pressure will be exerted on the stem, causing a crack to form. 1 One minor crack extends into the stem, major stubs or a branch of significant size.