Pin Oak Tree Diseases
The pin oak tree, also known as Quercus palustris, grows to a height of 60 to 70 feet and spreads 25 to 40 feet. It grows well in acidic soil and, once established, can tolerate wet soil conditions such as those found in high water table areas. It is well adapted to zones four through eight and thrives in partial shade or full sun.
The pin oak is susceptible to bacterial and fungal diseases that can cause damage or be fatal to the tree. Preventive measures include the use of insecticides and fungicides for routine maintenance and distance planting between oaks. Check your trees for indications of disease and treat early if infection is found.
Bacterial Leaf Scorch
Bacterial leaf scorch is caused by leafhoppers and spittlebugs, which transmit the Xylella fastidiosa bacteria to the tree, leading to a gradual decline in vigor. The first indication of the infection occurs after a season of drought. Bacterial leaf scorch interrupts the flow of water through the tree and causes red, yellow or brown margins to the leaves. Eventual leaf drop occurs. The progression of the disease can take place over 5 to 10 years, but ultimately affects the vitality of the tree.
Clemson University Cooperative Extension states that trees with extensive leaf scorch and dieback should be replaced. They also report that planting oak trees too closely together can lead to spread of the disease. No current treatment exists for leaf scorch, but root flare injections of antibiotic may be beneficial in suppressing the disease.
Anthracnose (Discula spp., Kabatiella apocrypta) is a fungal disease that overwinters in dead vegetation on the ground. It is spread in the wind and water during the spring causing lesions on leaves. Spore production leads to defoliation in the summer months of June and July. As the disease progresses, successive cycles of spore production occur. Spots may appear on leaves in the late spring, followed by leaf distortion and curling. The appearance of anthracnose is sometimes mistaken as frost damage in the early spring.
The University of Illinois Extension reports that anthracnose is seldom fatal and treatment is often unnecessary unless the tree has received extensive damage and major defoliation. Treatment for anthracnose usually consists of using a fungicide before buds emerge.
Oak wilt fungus (Ceratocystis fagacearum) clogs the flow of water and nutrients to the pin oak tree. The initial transmission of the disease is by the sap beetle, also known as the Nitidulid beetle, which attacks the vulnerable parts of the tree where prior damage has occurred. The fungus is then transferred from one oak to another by the close proximity of their root systems. Symptoms of oak wilt are pale limp leaves that eventually curl and drop.
Treehelp.com recommends destroying damaged trees and severing root systems of diseased trees to prevent the spread to healthy oaks. They also suggest limiting the amount of pruning done in the spring and early summer since this is the time when the beetle is most active.