Question: I noticed that a number of post oak
trees on my 20 acres
(trees not necessarily next to each other) where patches of bark
falling or has fallen off and a reddish brown powdery fungus(?)
evident. If I rub it or spray water on it, it easily blows off.
of these trees appear to be dead or dying. Is this in fact a fungus?
Will it spread to all the other trees? Is there anything reasonable
can do to kill the fungus or stop if from spreading?
Answer: The peeling bark is a classical sign
that the tree has
succumbed to Hypoxylon Canker. This stress related disease has
many trees as a result of the drought conditions that we have
under. There is no known control for Hypoxylon Canker other than
maintaining the tree in a healthy state. For more information
Texas Forest Service article found at