Bacterial Leaf Scorch (BLS) is a chronic and often deadly disease that affects several species of oak trees. Caused by the bacterium Xylella fastidiosa, this pathogen disrupts the tree's vascular system, preventing water and nutrients from moving efficiently throughout the canopy.
Oaks at Risk
BLS is known to affect several oak species, especially:
-
Pin Oak (Quercus palustris)
-
Red Oak (Quercus rubra)
-
Shingle Oak (Quercus imbricaria)
-
Scarlet Oak (Quercus coccinea)
-
Black Oak (Quercus velutina)
While white oaks are somewhat more resistant, they are not immune.
Symptoms of Bacterial Leaf Scorch
Symptoms typically appear in mid- to late-summer and worsen year after year:
-
Scorched or browned leaf edges, often with a yellow or reddish halo
-
Premature leaf drop
-
Uneven symptoms across the canopy, with some branches affected more than others
-
Progressive dieback over multiple seasons
-
Decline despite adequate watering
Because symptoms resemble drought stress or other environmental issues, BLS is often misdiagnosed without professional testing.
How It Spreads
The disease is spread by xylem-feeding insects, such as leafhoppers and spittlebugs. Once infected, there is no known cure. The bacterium remains active within the tree and spreads internally from year to year.
Why It’s a Concern
BLS causes chronic decline in infected oaks, often leading to death within 5 to 10 years. As the disease progresses, trees become structurally unstable, posing safety risks in residential or commercial areas.
Our Management Strategy
At Quality Tree Inc, we offer evidence-based management strategies to prolong the life of affected oaks and protect surrounding trees:
-
Lab Testing & Diagnosis: Confirm infection through laboratory leaf tissue analysis.
-
Pruning of Dead Wood: Improve tree appearance and reduce risk of falling limbs.
-
Nutritional Support: Boost the tree's immune response with deep root fertilization and soil amendments.
-
Vector Control: Apply treatments to reduce insect populations that spread the bacterium.
-
Annual Monitoring: Track disease progression and adjust care plans accordingly.
What You Can Do
If your oak tree is showing signs of leaf scorch, contact us right away. Early diagnosis and ongoing management can extend the life of the tree and slow disease progression.
​
📞 Schedule a tree health assessment today to protect your oaks from Bacterial Leaf Scorch.
