Q: Why do some people paint the trunks of trees white? A neighbor recently did this to three large trees in their front yard. I have seen this in the countryside and guessed it was to reflect light, so cars on a dark country road would not crash.
A: Pecan farmers sometimes paint the bottom of their trees white. When the trees are young, the southwest side of the trunk becomes hot on sunny January days. When temperatures drop at night, unprotected bark will crack. The white paint prevents heat build-up and averts tree damage. Old timers also believed that white paint would repel bugs by confusing them. I think most white-painted trees you see in the countryside are decorated because the owner thinks it looks cute or old-fashioned, not for traffic signals.