Bacterial Leaf Scorch
HIGHXylella fastidiosa
Overview
A chronic bacterial disease that affects many shade tree species, particularly oaks, elms, sycamores, and maples. The bacterium is transmitted by xylem-feeding leafhoppers and spittlebugs and colonizes the water-conducting vessels, restricting water flow. Symptoms worsen each year as more of the canopy is affected. There is no cure.
- Type
- Disease
- Severity
- HIGH
- Source
- USFS
Symptoms
Marginal leaf browning (scorch) with a yellow or reddish-brown border between dead and green tissue, symptoms appear in mid to late summer, browning progresses inward from leaf margins, premature leaf drop, symptoms worsen each year affecting more of the canopy, individual branches show scorch before whole tree
Affected Species
Geographic Spread
Treatments
Antibiotic Trunk Injection
Trunk injection of oxytetracycline (Bacastat) can suppress symptoms for one to two seasons but does not cure the disease. Must be repeated annually.
Plant Health Care
Maintain tree vigor through proper watering, mulching, and fertilization. Remove severely declining trees and replace with resistant species. There is no cure for bacterial leaf scorch.
Recommended Products & Tools
Helpful supplies for managing Bacterial Leaf Scorch. Always read and follow label directions, and confirm a diagnosis before treating.
Protectant spray for many bacterial and fungal diseases.
For the rare case sealing is advised (e.g., oaks in oak-wilt season).
Sharp, clean cuts to remove affected wood — a tree-care essential.
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Frequently Asked Questions
What is Bacterial Leaf Scorch?
A chronic bacterial disease that affects many shade tree species, particularly oaks, elms, sycamores, and maples. The bacterium is transmitted by xylem-feeding leafhoppers and spittlebugs and colonizes the water-conducting vessels, restricting water flow. Symptoms worsen each year as more of the canopy is affected. There is no cure.
What are the symptoms of Bacterial Leaf Scorch?
Marginal leaf browning (scorch) with a yellow or reddish-brown border between dead and green tissue, symptoms appear in mid to late summer, browning progresses inward from leaf margins, premature leaf drop, symptoms worsen each year affecting more of the canopy, individual branches show scorch before whole tree
Where is Bacterial Leaf Scorch currently found?
Bacterial Leaf Scorch is currently active in District of Columbia, Delaware, Georgia, Illinois, Indiana, Kentucky, Massachusetts, Maryland, Missouri, North Carolina, New Jersey, New York, Ohio, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, West Virginia. It has been reported in 19 total states across the United States.
What plants are affected by Bacterial Leaf Scorch?
Bacterial Leaf Scorch affects Red Oak, White Oak, American Elm, Sugar Maple, Red Maple, American Sycamore. Susceptibility varies by species.
How do I treat Bacterial Leaf Scorch?
Treatment options for Bacterial Leaf Scorch include: Antibiotic Trunk Injection, Plant Health Care. Treatment approaches may include chemical, biological, cultural, and mechanical methods depending on the severity and context.