Central Texas Oak Wilt Crisis


FEB 15 and APR 15

We all know the significance of April 15th every year but February 15th is a date you need to pay attention to as well. Why? Keep reading to find out if February 15th should be noted on YOUR calendar.

We all enjoy the ambience as well as relief from the hot Texas sun that our oak trees provide. Did you know that Central Texas oaks, of all varieties are facing a crisis of epidemic proportions?

It’s true!

If your property has oak trees, especially Red Oak (also known as Texas, Shumard, Blackjack & Water oak) or White Oak (other names include Post, Bur, Mexican, Durand, Lacey & Chinkapin) or Live Oaks, please note there is a fungus that is invading these trees.

This fungal infection’s scientific name is Ceratocystis fagacearum or as most refer to it…Oak Wilt.

This disease shrivels the leaves and causes discoloration as it kills the tree.

It’s caused by a fungal infection that disables the trees’ internal water system.

It is spread from tree to tree by way of insects that are attracted to the fruity odor produced from infected trees that develop a “fungal mat” under the bark’s surface. The insects pick up the spores on their body and transfer the fungus to the next oak they visit whether healthy or diseased. Several types of beetles are known for this activity.

The fungal mats develop when the tree has been wounded. Our Texas storms cause these wounds via hail and flying debris during high winds. Even squirrels and birds cause wounds. Vehicle impacts open the bark as well as pruning.

You can find fungal mats by looking for small narrow cracks in the bark that lead to hollow areas between the bark and the inside wood. The decaying wood will smell like decaying fruit.

To keep damaged areas safe, the wounded area should be treated immediately with latex or oil based paint that can be sprayed or brushed on the affected area to keep the damage from progressing. Click here for TAMU 8 Step Mgmt Oak Wilt

Another preventative measure you can take is, only buy well-seasoned firewood. Wood that has dried for a full year no longer has a live fungus that the insects can transport. When you cut down or prune an oak, treat the stump and fresh branches with latex or oil based paint to keep the insects away, whether the tree is infected already or not. You’re stopping the process of contamination. A diseased tree that’s cut down should be run through a chipper or burned. Transporting diseased wood should never be done because the fungal spores become airborne. If you chop your own firewood from oaks, use only wood from non-infected trees. Cover the pile with clear plastic and bury the edges well into the dirt, to keep fungus carrying insects from entering or leaving. After the wood has cured you can remove the plastic. If you have fresh chopped wood from a diseased tree, it should be covered in the same manner. Never store infected wood near healthy trees. Click here for TXOakWilt.org 

So what are the signs that an oak has oak wilt?

White oaks (the ones with the rounded leaf edges) are less prone to the infection but can live for several years after showing symptoms of the disease, losing only a few branches each season.

Live oaks develop yellow veins in the leaves that eventually fall from the tree. This is called “veinal necrosis”. Initially these leaves show a darker green vein known as “vein banding”.

Red oak symptoms are less dramatic. The young leaves simply wilt, turning pale in color, then brown as they die. If the leaves manage to mature, they soon pale in color then, starting along the edges, the brown color progresses inward then the leaf falls from the tree.

All oaks are vulnerable but the red oak is the most susceptible with the live oak in a close second.

While white oaks can sustain life for several years, the varieties of red and live oaks can be dead in as little as 3-6 months. Younger trees can die within a year.

Now…why is February 15th an important date?

Pruning of oak trees should only be done during the cold of the winter or during the prolonged heat of the summer months. These are the times of the year when the fungal activity is the least likely to spread.

February 15th through the end of June is the time to leave your oaks alone…no pruning!

If your oaks need pruning, give us a call and we’ll trim back those unwanted branches that are rubbing the paint off your house or that are interfering with power lines. While we’re there we can check your trees for various rot and especially oak wilt symptoms among your oak trees.

Help the oak tree population by doing your part in identifying and taking action to stop the spread of this disease. Contact us at 214 724-2294