Lisa's Landscape & Design

Saving the Planet One Yard at a Time

Oak Wilt, an Epidemic in the Texas Landscape

Live Oaks are a Texas landmarks.

Live Oaks are a Texas landmark

Oak trees are an exquisite staple in the Central Texas landscape. Many home owners inherit these beautiful trees with the purchase of a home which cost a premium because they add value to your property, provide shade and homes to wildlife. Unfortunately, these beautifully statuesque giants are being taken down by a beetle the size of a gnat. As a home owner with Oaks it is important to understand how Oak Wilt is spread. Oak Wilt is currently at epidemic proportions in central Texas and it is very important that all of us with Oak Tree’s pay attention.

Mature trees add value to your home

Mature trees add value to your home

Oak Wilt is not “caught” by the wind blowing or from another tree in the traditional sense. Oak Wilt is caused by a Vector. In this case it is the Nitidulid Beetle. (say that three times fast) 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, lightening strike, etc, and by simply landing on the fresh-cut wood with the fungus on its feet, 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.

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.  Only trim from February to June if it is absolutely necessary and if you must trim, be sure you are always spraying each cut as you go (this is true all year). Cut…Spray…, Cut… Spray… no exceptions. You can seal the wound with any latex house paint or a tree sealant purchased at any big box store or local nursery. If you are hiring a tree service, or 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. Anything else is unacceptable!!! I see a lot of services that make all the cuts then go back to spray, this is a NO, NO! The beetle could have already done its damage by the time you have finished the job, so cut and spray as you go.

Beautiful and majestic

Beautiful and majestic

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 comes to your property, watch them clean their tools and insist they clean between trees. You can clean your 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. My Crew are trained in Oak Wilt and know the drill and you will pay a premium for my service because we have insurance and a trained staff, but the loss of a mature Oak tree can cost thousands of dollars to remove and replace. 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 also want to watch for the signs in your neighboring trees. Oak Trees have enormous roots only a few feet below the surface that stretch out for hundreds of feet and can graft to one another, thereby exposing the next tree to the disease and so on.

Check out the National Forestry Service info 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, and this process can also be found on Google. This is supposed to prevent Oak wilt for up to three years. 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.

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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