Oak Wilt Management

Oak Wilt is a disease caused by a fungus that attacks and can quickly kill oak trees. Red oaks are very susceptible to Oak Wilt. While different species of oak respond to the disease in different ways, all oaks are susceptible, and Oak Wilt has already killed millions of Texas trees.

The fungus that causes Oak Wilt, Ceratocystis fagacearum, can be spread through the roots of adjacent trees or through insect activity. While some species, particularly red oaks, die quickly after infection, other species may live for many years after initial infection, allowing Oak Wilt to be transmitted to other oaks in the area. Dead wood from infected trees (such as firewood from red oaks) can also help to spread Oak WIlt, as it becomes a target for the insects (such as sap beetles (Nitidulidae)) that can transfer the fungal spores to living trees.

Because Oak Wilt is prevalent in Texas, the ISA has created a special training course for Texas Certified Arborists. At Texas Tree Surgeons, all of our Certified Arborists are Texas Oak Wilt Qualified or Certified, meaning they have passed an examination on Oak Wilt causes, prevention, and treatment administered by the ISA. Furthermore, they must maintain their credentials through continuing education and re-training. As research on Oak WIlt management and treatment continues in Texas, our Certified Arborists remain at the forefront of their field.

There are several areas in North Texas and the DFW area that have had recent Oak Wilt activity. These include:

• Preston Hollow, Dallas
• Lakewood, Dallas
• Walnut Hill and Abrams, Dallas
• Coit and Campbell, Richardson
• President George Bush Turnpike and the Dallas North Tollway
• Park and US 75 in Plano
• Highland Park
• University Park

Even if you are not in an area with current Oak Wilt activity, Texas Tree Surgeons recommends following general Oak Wilt precautions:

• Do not trim oak trees between the months of February and July
• If oaks must be trimmed during Oak Wilt Season, seal pruning cuts where possible
• Clear out dead wood from oaks and take care not to cause unnecessary open wounds
• Do not keep red oak firewood

For those of us in neighborhoods with Oak Wilt activity:

• Protect all trees, and especially oaks, against insects
• Be aware of dead and dying trees and advise neighbors to remove dead wood from their property
• Connect with neighbors to help improve awareness
• If Oak Wilt is within 100 feet of your trees, consider preventative treatments

How do you know if Oak Wilt is in your area? Keep your eyes open for these signs and symptoms:

• Dead wood or defoliation in oaks
• Production of small leaves on trunks and large limbs after dieback
• Leaves with browning at edges (red oaks) or along veins (live oaks)
• Fungal mats forming on surface of wood, starting out gray- or buff-colored and turning black as they age
• Cracking and peeling bark
• Visible insect activity

While these signs do not necessarily indicate Oak Wilt, presence or one or more of them may indicate potential issues. A visit from a Texas Tree Surgeons Certified Arborist can help you to understand the health of your trees and plan out your next steps.

If you decide, after discussions with a Certified Arborist, that a Plant Health Care program would be best for your trees, Texas Tree Surgeons has a range of plans that can help your tree fight off insects, bolster its natural immunity, and even offer some Oak Wilt-specific anti-fungal treatments. Texas Tree Surgeons closely follows research and guidelines put out by the ISA and the Texas Forest Service to make sure we can provide the best in Oak Wilt prevention and management.

For more information, visit https://texasoakwilt.org or contact us to set up a visit from a Certified Arborist.