Q: In the last few weeks, we have noticed that oak trees are shedding their bark profusely. The bark is simply falling off the trees in bits and pieces. What is happening to our wonderful trees?
A: There are two possible explanations. The first is that the trees have simply had two drought-free years of growth and the trunks are expanding more rapidly than the bark can accommodate. Another possibility is that the trees have smooth patch disease. This fungus decomposes the outer bark of trees, particularly white oak, and causes it to slough off. After a storm you might see several large pieces of bark at the base of the tree. Neither condition hurts the tree. If your oaks have full canopies there is no need to worry.
Lisa M. adds a third explanation: “I, too, noticed one of our oaks had patches of bark all over the ground and was wondering if it could possibly be diseased (the canopy is fine). My husband told me it was from squirrels and pointed out that a lot of the oaks in our back yard were shedding their bark. I was skeptical at first, but, sure enough, a few minutes later a squirrel ran up and started pulling patches of it off. I can only surmise they must be eating bugs or something underneath.”