Symptoms: Cracks develop in a longitudinal (up and down) manner on the trunk often on the south, southeast or, occasionally, west side.

Diagnosis: This type of damage is called frost cracks. They are caused when the sun shines on the bark during an otherwise very cold winter day. There is just enough heat generated to expand the bark but not warm the wood beneath. This causes a stress that results in the splitting of the bark. The split may pull back together when the weather warms but it will still be quite visible.

Perhaps the most serious ramification of frost cracks is not the small crack themselves. Rather, it is the fact that most of these cracks will develop a fungal infection called a canker which will make them larger and cause a decline in the overall vigor of the tree. They will not kill the tree but will shorten its long-term survival.

Young trees with smooth bark are most susceptible to frost cracks. Certain species are most likely to suffer cracks including:

Acer sp. Maple Prunus sp. Peach, Cherry
Aesculus sp. Horsechestnut Salix sp. Willow
Liriodendron sp. Tuliptree Tilia sp. Linden
Malus sp. Apple or Crapapple Ulmus sp. Elm
Platanus sp. Planetree    

Treatment: There really is no good treatment once the crack has formed on a young tree. However, prevention may be attained by using light colored tree wraps on the trunk until it starts to form its coarser textured, mature bark.


Note: We have provided some general information and observations on this topic aimed at the home gardener. Before you take any serious action in your landscape, check with your state's land grant university's Cooperative Extension Service for the most current, appropriate, localized recommendations.


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