oak tree If you are a homeowner who has an oak tree, or several, on your property, you may have noticed that something hasn’t been quite right. During the summer, we usually expect all of our foliage to turn green and lush, providing us with much-needed shade and shelter during the heat of the season. Sadly, many oak trees in Pennsylvania (and along the eastern seaboard) have been affected by something known as, “Bacterial Leaf Scorch.”

What is Bacterial Leaf Scorch

Bacterial Leaf Scorch, sometimes called Marginal Leaf Burn, refers to a condition when the outer edges of the leaves are not getting sufficient moisture for one reason or another. Some of these reasons may include:

  • Insufficient moisture in the soil
  • Water is lost too quickly from the leaves
  • Roots have been killed by plant pathogens, excavation, or compaction
  • Fungi or bacteria invade and plug the water-conducting vessels (xylem) in the plant

One primary culprit in Pennsylvania is a bacteria known as Xylella fastidiosa. Xylella can inhibit water from reaching the leaves of oak trees. This will turn the leaves of an oak tree brown, even in the spring and summer. The only real way to know if your trees are affected by this bacteria, or have Bacterial Leaf Scorch, is by contacting a professional, as they can perform accurate testing to confirm bacterial presence.

How it Spreads

Because BLS is caused by bacteria or fungi, the disease can be transported to other trees near the diseased plant by beetles, grasshoppers, and spittlebugs.

Protecting Your Oak Trees

Unfortunately, once your oak tree is suffering from Bacterial Leaf Scorch, there is no way to cure it. Even though it takes years for the bacteria to fully kill an adult oak tree, it can be unsettling and devastating to watch your trees die. Some treatments that help the trees keep their green leaves include an antibiotic called ‘Tetracycline’, but this treatment only postpones the inevitable and can be costly.

Hypoxylon Cankers Threatening Oak Trees in PA

hypoxylon cankers In addition to Bacterial Leaf Scorch, Hypoxylon cankers have been causing the deaths of oak trees around Pennsylvania. These cankers, in the form of lesions or spores, infect the bark of the tree and literally rot the tree from the inside. These spores can range in color from light blue to black and can affect weak trees as well as healthy ones.

Over time, the structural integrity of the tree is compromised. Although it can take up to 8 years for these lesions to kill an oak tree, just like with BLS, it is not something any homeowner wants to experience.

Keep Your Trees Alive and Healthy

To keep these diseases and spores at bay, it is vital to keep your trees pruned and healthy by using a trusted and professional tree service that can identify issues early to provide treatment. At Mr. Tree, we love providing resources that keep our tree populations alive and thriving. If you need our services or suspect that one of your oak trees may be infected with Bacterial Leaf Scorch, or is showing signs of lesions, please contact us right away.