Lisa's Landscape & Design

Saving the Planet One Yard at a Time
Oak wilt affected oak tree

Oak Wilt in the Central Texas Landscape

Where Does it Start?

Oak trees are an exquisite staple in the Central Texas landscape. Many home owners are drawn to properties because of these beautiful trees. Properties with mature trees cost a premium because they add value to your property, provide shade, save energy and homes for wildlife. Unfortunately, these beautifully statuesque giants are being taken down by a beetle the size of a gnat.

Mother Tree

What Do I Need To Know?

As a home owner with Oaks it is important to understand how Oak Wilt is spread. Oak Wilt is pretty rampant in central Texas so it is very important for all of us with Oak Tree’s to pay attention.

Mature trees add value to your home

Mature trees add value to your home

Oak Wilt is a fungus that is caused by a vector which in this case is the Nitidulid Beetle. The beetle lands on a fungal mat formed on an already infected Red Oak tree and carries the disease to a fresh wound, untreated cut, mower injury, weed eater nick, or lightening strike. This beetle is attracted to a fresh cut by the fruity smell which it can sense from a 1/4 mile away. By simply landing on the fresh-cut wood with the fungus on its feet, it infects the tree. The fungus clogs up the vascular system of the tree and in Red Oaks, (having a larger vascular system) it is certain death, usually in about 3 weeks. In a white Oak, due to its much smaller vascular system (think of it as drinking from a tiny straw), it can take several months or longer to show signs.

How Is It Prevented?

There are a few very simple practices that help prevent the spread of Oak wilt. The recommended time to trim your Oak Tree’s is from July 1st through January 31st. Trimming from February to June can be done if it is absolutely necessary but be sure you are always spraying each cut as you go (this is true all year) with a tree sealant (below) or latex paint if that’s all you have. Cut…Spray…, Cut… Spray… no exceptions.

If you are hiring a tree service/Arbor, or if City Utilities are trimming in your yard, you need to be your own advocate. Do not assume the tree service or utility company is practicing this method. I see a lot of services that make all the cuts then go back to spray, this is impractical and nearly impossible to find. The beetle could have already done its damage by the time you have finished the job, so cut and spray as you go.

How do I Prevent it From Spreading?

Equally important is for you or your service to clean the tools before they begin and between each tree trimming. A diseased tree can spread the fungus to another non diseased tree by using contaminated tools, and a White Oak Tree can be sick for several months before showing the signs. If a tree service/Arbor comes to your property, make sure they’re Oak Wilt Certified, make sure they clean their tools before and between trimming trees. You can clean your own tools with a can of Lysol, bleach or alcohol. Remember that this is a fungus, so you are killing the spores that may be on your tools before you contaminate another tree. While a licensed Arbor may be costly, the loss of a mature Oak tree can cost thousands of dollars to remove and replace.

Can My Trees Be Affected by My Neighboring Trees?

For the sake of time I encourage you to Google Oak Wilt images and educate your self about the “signs” of Oak Wilt. There are very specific features a red or white Oak Tree will have when it has Oak Wilt. You want to watch for the signs in your neighboring trees and leaves. Oak Trees have enormous lateral roots buried only a few feet below the surface that stretch out up to a hundred feet in any direction causing them the graft with neighboring trees. This grafting  can expose the next tree to the disease and so on.

Where Can I Learn the Signs of Oak Wilt?

Check out the National Forestry Service for more information on Oak Wilt and the manner in which it can spread. You can also contact your local Agrilife Extension Office to see if they can send out a Master Garden such as myself who is certified in Oak Wilt to diagnose your tree’s problem. There is a method to prevent Oak Wilt by infusion where you inject a product called “Alamo Fungicide” (There are other fungicides as well) into the root flairs at the base of the tree. This process can also be found online. This protocol is also supposed to prevent Oak wilt for up to three years if Oak Wilt is in your area. Your local Agrilife office may have newly certified volunteers who are able to come train you in how to inject your trees as part of their certification process.

Plant For Diversity!

A key note here is that Live Oaks have been over planted by builders and home owners who aren’t sure what else to plant. It is essential to our ecosystem to diversify in the landscape with native and adapted trees and plants for the best results all around. 

Now go plants some trees!

For more information, please contact http://txforestservice.tamu.eduor or

Lisa LaPaso

Lisa’s Landscape & Design (“like” me on Facebook!)

“Saving the Planet One Yard at a Time”

Check me out on YouTube!

quote of the day: “He who plants a tree loves others besides himself.”- Unknown


  1. Cavin

    Thanks Lisa the Lorax!

  2. I love reading through an article that will make men and women think.
    Also, many thanks for allowing me to comment!


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