Sun Scald
You might sometimes notice that some chunks of a tree’s bark buckle and look as if they are about to fall. In gardening terms, that process is called Winter Sun Scald or Southwest Injury and usually occurs during the tree’s infancy. But what causes this phenomenon? Simply put, Sun Scald happens in areas such as New Mexico, where there is intense sun exposure, and the temperatures fluctuate wildly between day and night.
Fortunately, painting a tree’s trunk white is similar to adding sunscreen. In other words, once you whitewash your young trees, their trunks’ surfaces won’t get dry and cracked as easily anymore.