Pin oak trees are large shade trees that have an oval-pyramidal shape with glossy, dark green leaves. If given the proper growing environment, a pin oak can grow to be 70 feet tall. Pin oaks prefer full sun and are tolerant of many environmental problems such as flooding and heavy clay soil. However, many diseases can severely damage and even kill pin oak trees.
Bacterial Leaf Scorch
The bacterium Xylella fastidiosa is the cause of the fatal bacterial leaf scorch. Leaf and tree hopper insects spread the bacterium that causes leaf scorch from tree to tree. There is no treatment that will save a pin oak tree that is infected with bacterial leaf scorch. However, you can prune back the dead branches to keep the tree looking presentable. Symptoms of bacterial leaf scorch include a browning of the leaves that is separated by a yellow line.
Pin oaks are often susceptible to chlorosis, which is an iron-deficiency in the soil surrounding the tree. Chlorosis typically occurs in soils that have a high pH level. The first signs of chlorosis are a yellowing of the leaves accompanied by dark green veins. If the pin oak is not treated, it will succumb to the chlorosis and die. Fortunately, chlorosis is treatable by a variety of methods. A landscaping company can treat the pin oak tree with an internal systemic treatment of iron and zinc. Alternatively, you can apply iron chelates to the soil around your pin oak tree in the spring when the buds are beginning to form. The chelates work to raise the amount of iron in the soil, which will, in turn, raise the amount of iron the pin oak is absorbing.
Cankers are a fungus that attacks the branches and trunk of the pin oak tree. Typically, cankers will form after the tree has gone through some form of stress such as wounds, low fertility and drought. Stress weakens the overall health of the tree and makes it more susceptible to fungus such as cankers. Keep cankers at bay by fertilizing the tree regularly and perform routine pruning of dead and diseased branches.
A crinkling and paling of the leaves could be the first stages of oak wilt. Oak wilt is a fatal disease that will cause the leaves of the pin oak to wilt and turn brown as it moves towards the center of the tree. Pin oak trees that are infected with oak wilt can die within a few months after the initial contact with the fungus. There is not one method that is successful in every oak wilt case. However, with the proper pruning you may be able to stop the spread of the oak wilt and keep your tree alive.