Oak Wilt Disease: Everything You Need to Know

Oak Wilt Disease

Texas is famous for its towering oak trees. Oak trees are great shade providers in the summer and transform beautifully in the fall. With care, oak trees can live a healthy life for hundreds of years.

Unfortunately, many oak trees in Texas fall victim to Oak Wilt Disease. Oak Wilt Disease is a fungal disease that can spread through a tree’s vascular system, and it may get worse after the winter’s ice storms.

Once Oak Wilt takes hold, it can cause permanent damage within a matter of weeks. With the help of the Oak Wilt specialists of Texas, you can help stop the spread.

Ready to learn more about Oak Wilt Disease? Read on for our complete guide.

What Is Oak Wilt Disease?

As we mentioned already, Oak Wilt is a fungal disease that takes over a tree’s vascular system. The vascular system of an oak tree is the network that carries water from the roots to other areas of the tree, including the leaves. Once that fungal disease gets into the vascular system, it blocks the passage of water, leading to rapid leaf death and loss.

Oak wilt disease has killed more than one million oak trees across Central Texas. All oak trees are susceptible to Oak Wilt, but Red oaks are most likely to die once infected. White oaks are more resilient in the face of Oak Wilt and rarely die, while Live oaks fall somewhere in the middle. 

How Does Oak Wilt Disease Spread?

There are two primary ways that oak wilt can spread. If you have several oaks on your property and only one is showing signs of oak wilt, it’s likely “patient zero” and got oak wilt from sap-feeding beetles in the nitidulid family.

These beetles are attracted to the sweet-smelling fungal mat that develops beneath an infected oak’s bark. As they traverse infected trees, spores stick to their bodies and stay there. They then spread those spores to otherwise healthy trees while seeking their sap from open cuts and wounds. 

Once one tree in a grove or forest has Oak Wilt, the surrounding trees are in danger. Oak Wilt can continue to spread through a shared or grafted root system at a rate of about 75 feet per year.

Signs of Oak Wilt Disease

Because Oak Wilt is such a fast and wide-spreading tree disease, it’s important to take note of any signs of Oak Wilt right away. These signs are easiest to spot in Red oaks, while other types of Oak trees may exhibit only microscopic symptoms.

The most noticeable symptom of Oak Wilt, particularly in Red oaks, is the sudden discoloration of leaves. They may fade to a dull green or bronze color, followed by a yellow or brown color. Then, the leaves may start to drop by the hundreds, leaving the branches bare.

In Red oaks, you may also notice that fungal mat we referenced earlier. Because it grows beneath the bark, you’ll only notice it if it starts to crack or raise the bark from the trunk. 

Many property owners notice signs of Oak Wilt in one tree and think it’s an old tree that has reached the end of its lifespan. It’s only when they notice a huge shift in tree health across their property that they realize that they’re dealing with a disease. With proper care, you don’t have to lose all of your oaks to Oak Wilt.

Preventing Oak Wilt Disease

One of the most important things you can do is practice proper tree care that can help prevent the spread of Oak Wilt through sap-feeding beetles. That means no pruning or trimming during the oak’s primary growth cycle.

In other words, don’t prune or trim your trees in spring, summer, or early autumn. Instead, trim during the dormant period, which tends to span from November to mid-March. Pruning and trimming can encourage better growth and increased tree health, but only when done properly and at the right time of year.

Managing Oak Wilt Disease

Not everyone learns about Oak Wilt early enough to take preventative measures. In fact, if you’re reading this guide, it’s probably because you suspect that one or more of your trees already has the disease. Let’s talk about three ways that you can manage Oak Wilt so that it doesn’t wipe out your entire property.


The first step in Oak Wilt treatment is to get a diagnosis from a professional arborist. The symptoms of Oak Wilt are easy to confuse with the symptoms of other tree diseases and issues that could require a different approach. If you’re not an arborist, don’t start treating your trees for Oak Wilt until you know that’s what you’re dealing with.


One method to manage Oak Wilt spread is to inject healthy oaks. Chemicals designed to mitigate the spread are injected into the roots of healthy oak trees. You typically will not inject the roots of an infected tree, as the injection is less effective at fighting an infection that has already taken hold.


Oak Wilt trenching is another common method used to manage the spread of Oak Wilt. Trenching is the process of digging a deep trench around the infected tree. This will sever the connection its roots have made with other trees, cutting off the path the disease would otherwise follow.

Hire Our Oak Wilt Service in Austin

Oak Wilt Disease has killed over one million oak trees in Central Texas and can do serious damage to the beloved oak trees on your property. If you suspect that one or more of your trees have Oak Wilt Disease, don’t hesitate to seek professional services.

Oak Wilt RX is proud to serve property owners in Austin and surrounding areas. Contact us today to schedule our Oak Wilt and tree care services.