Protect newly-planted trees from freezing injury

Left  photo is Sun Scald

Right  photo is Frost Crack

Freezing can result in bark splitting. During the winter or early spring, sharp temperature changes between day and night can freeze the water within the trunk causing it to explode or split open in a symptom referred to as “frost crack.” Frost cracks are also called southwest injury since this is the side of the tree most often affected. Bark splitting can occur on the trunk or branches of trees.
A related problem is “winter sunscald”. This type of injury occurs when the sun warms the tree bark during the day and then the bark rapidly cools after sunset. This results in bark splitting or cracking.
Newly planted trees or young trees are more prone to trunk bark splitting. Secondly, thin-barked ornamental trees such as red maple and ornamental cherry are particularly at risk. Painting the trunk white with latex paint, wrapping it with tree wrap, or placing tree guards, can prevent splitting in young trees. If the guard is used, it should be loose enough to allow air to flow through the space between the stem and the guard. Many types of wraps are available in the market. In the absence of a commercial tree wrap or guard, wrapping trunks with burlap can also protect them from bark splitting. When you wrap the trunk, begin at the soil line and spiral the paper around the trunk up to the first branches, overlapping the edges of each layer. All wraps and guards should be removed in late spring to pre- vent girdling or insect damage. Newly planted trees should not be fertilized late in the growing season, as this may promote new growth and predispose the tissue to bark splitting. Bark splitting not only affects growth and development of the plant, but it also becomes the source of borer (insect) damages.

By Lala A . Kumar, Horticulture Specialist, West Central Region, University of Missouri Extension