How to Identify and Treat Oak Wilt in Central Texas

What is Oak Wilt?

Oak wilt is the most destructive fungal disease in all of Texas and one of the destructive diseases in the United States. This disease is caused by the fungal organism “Bretziella Fagecearum”. This organism infects and stops the water from conducting into the xylem system of oak trees.

All oak tree variations can be infected by oak wilt, but some species are more resistant than others. In order to manage this destructive disease proper diagnosis and a scientific understanding how this disease interacts with different oaks is paramount. 

How does it spread?

Oak wilt can spread through 2 major ways.

1. Sap Beetles

Physical contact with a family of sap beetles called Nitidulids. As shown in pictures below:

These beetles will find the scent of the oak wilt fungus and rub their bodies in the spores while feeding on the fungal bodies. They will then find wounds on oak trees and feed on the sap. This contact with the oak wounds will spread the fungal disease into the tree. For certain trees, such as Red oaks (shown below), this is the only way it has been proven for disease to spread.  

2. Root-to-Root Contact

Through connected roots of oak trees. This is the main and most common way the disease can spread. Some white oaks such as white shin oak, lacey oak, and chinquapin oak. Live Oaks are the most known for the disease to spread through the root system.  

How to Identify Oak Wilt

Shown in pictures below are symptoms from a proven live oak tree that has oak wilt that Levi Williams took in the field. 

Foliage discoloration

• Leaves may develop yellow or brown veins and fall prematurely

As shown below is the symptom that oak wilt causes on live oak foliage. 

‍‍Branch dieback

• Branches may die off from the tips inward

As shown below is common branch dieback symptoms on a live oak.

Another diagnostic tactic is to see what other live oak in the vicinity look like. Very rarely will you see just one live oak with symptoms of oak wilt. Live Oaks generally will all be affected by oak wilt in a given area with similar symptoms. 

With Red oaks they have similar symptoms in the canopy branches and foliage. As shown below.

Fungal mats shown below on the trunk of red oak.

Foliage symptoms shown below on red oak leaf.

The only way to truly know if its oak wilt on a possibly affected tree is to send samples to a laboratory for testing. Our certified arborists can handle this process for you. 

Can Oak Wilt Be Treated?

• ‍Red Oaks: Unfortunately, once symptoms appear, Red Oaks typically die within 4–6 weeks. They cannot be treated successfully after infection.‍
• White Oaks: These species tend to be highly resistant and may survive even without treatment. Monterrey Oaks, for example, have excellent resilience.‍
• Live Oaks: These trees can sometimes be saved with aggressive intervention. Without treatment, they typically succumb to oak wilt.

Live oaks can survive oak wilt, but generally will die from oak wilt at a high percentage rate without oak wilt treatments. 

Shown below is a picture of a common oak wilt chemical treatment method. 

Oak wilt can be treated preventatively before the disease is in the area once a year with a fungicide micro injection. Preventative treatment can greatly raise the percentage of the survival of your oak trees and is the only way to save Red Oaks from oak wilt.

Trees with oak wilt can be treated (live oak for example), as well with the same micro injection treatment with a fungicide every 7 months. 

Preventing Oak Wilt on Your Property

In order to plan for future oak wilt outbreaks there are multiple things you can do. Future proofing your property, by planting new trees such as oak wilt resistance varieties of oaks and non oak trees, such as cedar elms. This is a very easy and straightforward way of avoiding the affects of oak wilt and protecting your property.

Preventative oak wilt injections are also another fantastic option for treating oaks already on your property. 

Conclusion

If you are concerned about oak wilt in your property or area TREE SCOUTS TREE SERVICE can put you at ease. We have professional ISA certified arborists to help identify and treat oak wilt. We can give you a game plan so you can conquer OAK WILT!!!!

👉 Contact Tree Scouts today for a free oak wilt consultation and treatment plan.