Save your oaks - get free disease testing in Missouri

By Blake Jackson

Missouri residents can now get free testing for common oak tree diseases. The University of Missouri Extension’s Plant Diagnostic Clinic, in partnership with the Missouri Department of Conservation, is offering this service to help monitor and control oak health issues.

“With this service, we hope to collect information on the location and host species of oak diseases across the state,” says Peng Tian, director of the Plant Diagnostic Clinic on the MU campus. “We are also actively scouting for new or invasive diseases of oaks to better assist MDC and the Missouri Department of Agriculture with controlling forest pest problems.”

Oaks are a vital part of Missouri's forests and landscapes. Unfortunately, they are susceptible to several diseases, including bacterial leaf scorch and oak wilt.

Oak wilt is particularly harmful to red oaks, often leading to death within weeks. Bacterial leaf scorch is a chronic disease that weakens trees over time.

Symptoms of oak wilt in red oaks typically appear in late spring or early summer. Leaves may discolor, wilt, and fall, starting at the top of the tree. In white oaks, symptoms often appear later in the summer and may include isolated dead branches.

Bacterial leaf scorch affects the tree's vascular system, preventing water and nutrients from reaching the leaves. While there's no cure, symptoms can be similar to drought stress, making diagnosis difficult.

If you suspect either disease in your oak trees, Tian recommends sending samples to the Plant Diagnostic Clinic for testing. You can start by submitting photos online. The clinic staff will then provide instructions for sending physical samples if needed.

For bacterial leaf scorch testing, collect 20-30 leaves with leaf scorch symptoms and pack them in a sealed plastic bag with a damp paper towel. For oak wilt testing, collect branch sections with wilt symptoms and keep them cool during transport.

By participating in this free testing program, Missouri residents can help protect their oak trees and contribute to the overall health of the state's forests.

Photo Credit: university-of-missouri