Why Do People Paint Tree Trunks?
A reader asked this question. Here is what my research revealed: From E-How.com
If you have ever noticed a beautiful tree with a painted white trunk and wondered why someone would go through the trouble; there may be a good reason. The white painted bottom is rarely a decorative statement or an attempt to make the tree more aesthetically pleasing. It is, however, a practice that can potentially save the life of the tree. Trees can benefit from a coating of white paint when recent landscaping has entailed the removal of a larger tree that once provided shade for another, or the excessive removal of branches has left a tree barren and its trunk exposed to the sun's rays
The bark of trees is just as susceptible to sun damage as is human skin. Too much hot sun directed onto a tree trunk day after day may not leave behind a sun burn but it will cause damage to the bark that will become noticeable over time. Arborist Mario Vaden explains that sunscald is denoted by bark that cracks and falls off, or simply changes color. Wrapping the tree with a specially designed trunk cover or painting the tree trunk can prevent sun damage.
A tree borer is an insect that tunnels underneath the bark of a tree and cause severe damage to the underlying layers of the tree. Adult tree boring insects will even lay eggs under the bark; leaving larva to chomp away at the phloem (nutrient-transporting layer) of the tree. According to the University of California, a large infestation of tree borers feeding on a single tree can result in damage that can only be rectified by heavy pruning or removal of the tree. Tree boring insects often seek out trees with the weakest outer protection, so painting trees that are susceptible to sunscald can prevent bark damage and keep tree borers at bay.
According to the University of Missouri Extension, white latex paint can also be used to prevent the bark of a tree from splitting and cracking off. This can happen when the tree is exposed to freezing evening temperatures followed by a daytime thawing. The painted white trunk will help reflect sunlight during the daytime hours and keep the tree warmer at night.
Painting the trunks of trees is also helpful in deterring furry, four-legged vermin. There are some wild animals that feast on tree bark, causing severe damage to the trees that become their daily lunch. According to the University of Vermont, adding a small amount of rabbit repellent to the white paint can prevent hungry rabbits from gnawing on tree bark.
Contrary to popular belief, you do not need to use white paint to protect a tree trunk. In fact, Ed Laivo from the Dave Wilson Nursery reveals that any light-color paint can be used. What is important, though, is the type of paint used. Latex based paint that is used to paint the interior of your home is sufficient, but if you want to be "green" use paint that has an organic base. Never use an exterior paint because it contains fungicides that can harm the tree.