AUSTIN (KXAN) — Destruction wrought by an early-February ice storm locally felled many of our local trees and greatly reduced their canopies, opening wounds that could lead to more dead trees, arborists warn.

This threat is an annual one: oak wilt, a fungal infection that kills oaks by preventing water transportation through the tree. It spreads via contaminated tools, airborne spores, root systems and insects, often entering a tree through cuts and open wounds. It is an invasive, vascular infection, similar to the chestnut blight and Dutch elm disease.

Texas A&M Forest Service calls it “one of the deadliest tree diseases in the U.S.” and says the fugus is responsible for killing millions of oak trees across Texas.

  • A red oak tree beginning to change color, while trees nearby are still green.
  • An oak leaf turning brown near the tip.

Karl Flocke, a woodland ecologist with the Texas A&M Forest Service, says that we are currently in the oak wilt transmission season, which runs from February to June.

Master Arborist Vincent Debrock, co-owner of Heritage Tree Care, says that changing weather conditions can spread the fugus. As temperatures climb, insects that spread the fungus (predominantly beetles) awake from dormancy. High winds can pick up and spread spores.

Cleaning up from the Storm

Flocke and Debrock both said that damage from last week’s storm is “probably very low risk” for the fungal infection, as those wound have already naturally sealed. However, as the storm clean up continues, it is worth taking the extra time to disinfect tools and seal those wounds properly.

“As we proceed into the spring, further cuts to trees might open up wounds that oak wilt can be transmitted to so if at all possible, we don’t want to cut more than necessary on our oak trees,” Flocke said. “And any cuts made to oak trees should be immediately painted to seal over that wound.”

Any type of paint can be used to seal the wounds, so long as it completely covers the wound.

Tools that are used on oaks should be disinfected with rubbing alcohol or bleach spray. If bleach spray is used, Debrock says to wait 30 seconds after spraying before using the tool.

“It’s pointless to call someone now to seal breaks from last week,” Debrock said. “It is important to vet a tree services to make sure they know how to disinfect their tools. Be safe rather than sorry.”

Once ice storm-related damage is cleaned up and sealed, avoid pruning or other damage to oaks until after oak wilt season ends. Debrock encourages Austin residents to wait for professional help, if possible, before removing or pruning damaged trees.

“Just take care of any emergency cuts now, then call in professionals for the rest,” said Debrock, noting that obstruction to property access or utility lines are emergencies. “We can cut more later, but we can’t put it back.”

“Our city’s trees might not look as nice as they did last week, but our oak and juniper forest is very resilient,” Debrock said. “When working with trees, there are no do-overs. Tree time is slow time, so we have to be patient.”