TEXAS – Oak trees are a common site in many Texas yards, providing much needed shade for homeowners as well as habitat for native Texas wildlife. However, pruning the trees during the springtime can have unintended consequences that may leave trees in danger.

• Oak wilt is spread through tree wounds
• Infected trees can die within weeks of infection
• Millions of trees have died from oak wilt

Berny Schiff’s yard is full of oak trees. It’s one of his favorite things about his home. But those trees are under attack by a disease that has killed millions of oak trees across Texas.

“Oak wilt is an often fatal, fungal disease that affects oak trees throughout Texas,” explains April Rose, the Urban Forest Health Coordinator for the City of Austin.

It’s a brutal disease that disables the water conducting system and is sometimes spread when roots graph together underground.

The disease can be spread any time of year but circumstances are perfect in the spring, according to the Texas A&M Forest Service, which recently issued the following statement about the disease: 

“Spring is the time of high fungal mat production, high insect populations and the highest susceptibility to disease for oaks.”

There are ways to prevent the spread of the disease. The first is to avoid pruning during the spring. Oak wilt can also be found in spores under the bark of an infected tree. When there is damage to a tree, sap eating beetles that may be carrying the disease bring the spores with them, infecting the new wounded oak.

But if an oak tree does get wounded and bark is removed, there is a simple step a property owner can take to try and prevent the spread: paint. The Texas A&M Forest Service recommends painting over tree wounds, stating any kind of paint will do. This deters bugs that may be carrying the disease.

How to tell if your trees may be infected: Different types of oak trees show different symptoms. For live oaks, the telltale sign is veins on the leaves. If you have red oaks, the Forest Service says the signs are a little less distinct:

“In early spring, young leaves simply wilt, turning pale green and brown, usually remaining attached for a period of time. Mature leaves develop dark green water soaking symptoms or turn pale green or bronze, starting at the leaf margins and progressing inward.”

Rose says that if you think your trees are infected, it’s important to contact a certified arborist right away because the timing for treatment can be tricky. She also adds it’s important to communicate with neighbors to help stop the fungus from spreading.

As for Schiff’s trees, many are too far gone.

“All of these trees, we were waiting for them to really leaf out and they never did," Schiff said. 

But he’s working to try and save the ones that aren’t infected as well as stopping the spread.

You can learn more about oak wilt and find contact information for a forester in your area by visiting texasoakwilt.org.