I planted what I hoped would become a big, beautiful maple tree someday, but a year after planting, the bark on the trunk has a huge split in it. Is it a goner? JJ

Young, thin-barked trees (like maples) are susceptible to a condition we call Southwest Tree Injury. While there is no fix for your damaged tree, here is some information that will help you prevent this from occurring on trees you plant in the future.

As we have said many times, the fall is the best time to plant new trees and shrubs because if gives them all winter to develop a healthy root system before having to face our Oklahoma summers. However, when planting young, thin barked trees like maples, you will need to take some extra precautions. Here’s why.

During the winter, the afternoon sun shines on the southwest facing side of the tree. This causes the bark on that side of the tree to warm up and expand. Then, in the cold of the night, the bark contracts. As this process repeats each day, (expand, contract, expand, contract) the bark can be damaged, and this damage causes the bark on young, thin barked trees to split. The vast majority of these trees do not recover from this damage. As a result, the trunks of these damaged trees will remain split for the remainder of their often-shortened life.

To see this type of damage on trees, all you need to do is visit any parking lot that had young trees planted during the construction process. The damage is often exacerbated in these parking lots because the young trees get kind of a double whammy of damage due to the direct light from the sun and the reflected heat generated from the typically asphalt parking lot. If the trees have been there a few years, there are almost always a few that have already died.

Trees most susceptible to Southwest Tree Injury would include cherry, maple, weeping willow, and a variety of fruit trees. To prevent this type of damage, these newly planted trees should have their trunks wrapped with tree wrap in the winter. Tree wrap should be available at most local garden centers.

When wrapping your young tree, you don’t want to wrap the trunk too tight because you want a little air circulation, but the wrap should be tight enough to keep the wrap securely in place. As it begins to warm up in the spring, remove and save the tape to re-apply in the fall.

This process should be repeated for the first two or three years after planting a tree. After this point, the bark of the tree should be strong enough to fend for itself, so to speak.

If you tree is already damaged with Southwest Tree Injury, there is nothing you can do to heal the wound. Many trees can recover from damage to the bark, but these injuries tend to remain throughout the life of the tree. Your best strategy for a damaged tree is to keep it healthy with good watering and fertilization practices. Good luck.

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org.

Photo: Tom Ingram