Question
I live in central texas and the land is covered with oak trees. I have recently noticed several trees loosing bark. One tree had a small spot missing and the other day it lost a section of bark that was about 4 times larger. Is this natural or maybe due to the constant droughts? Or are the trees diseased? I cannot afford a tree service at moment but I do not want to loose them either. Any help would be apperciated.

Answer
It is drought related and the tree are under stress and more than likely has be infected by a disease called Hypoxylon canker. The major signs of Hypoxylon canker are stem or branch dieback and patches of bark that fall off the tree. Wood surfaces beneath the displaced bark may be whitish-grayish in color due to the presence of the fungus and sometimes a black crust-like form of the fungus is also visible. The fungus is more likely to infest oaks that have root system injuries or diseases or have been weakened or stressed by such factors as drought, poor nutrition, soil compaction, or construction damage.

Control is achieved by maintaining the trees in a healthy condition. Avoid injury to the trunk and limbs and never apply fill soil around the trees. Chemical treatments would not be effective because the fungus is located within the tree. I would suggest that you call the local office of the Texas Forest Service (state agency) and ask one of their Forester to come out and take a look. This is a free service and they can tell you if anything should be done. Their phone number should be in your local book.