Texas Oak Wilt Prevention

Texas Oak wilt (also called oak decline) is caused by a fungus. On red oaks, one of its main symptoms is discoloration of the leaves which starts at the outside edges and progresses inward. On live oaks, the veins of the leaves die first, becoming yellow or brown. A pervasive tree disease, the prevention of oak wilt is important since once symptoms are present there is no way to keep the tree from dying. Any type of oak tree may contract this fungus, but some are more susceptible to it than others. Red oaks, the Spanish oak in particular, is most vulnerable. White oaks may get it but are more resilient and usually don’t die from it. Live oaks fall in the middle of the spectrum.

How Does It Spread?

Oak wilt spreads in two ways: through certain types of beetles which carry the fungus to other oaks (sometimes over long distances) and through the interconnected root systems of live oaks. The beetles are attracted to oaks infected with the disease because the fungal growths give off a sweet smell. Not only can they spread the fungus from tree to tree, but they can carry it from infected firewood and transmit it to the healthy trees in your yard. Oak wood needs to cure (be allowed to dry completely) for a whole summer to be considered safe to store anywhere near your healthy trees. However, it’s not a problem to burn contaminated logs from a sick tree you’ve cut down, since heat destroys oak wilt.

Prevention

• The best way to prevent oak wilt is to paint all wounds on your oak trees. This includes cuts made from pruning and machinery such as weed eaters, mowers, etc. You should use special pruning paint for this which is safe for trees and seals the wound.
• Avoid pruning between February 1st and July 1st when the fungus-carrying, sap-feeding beetles are most active.
• Sanitize pruning tools using cleaning alcohol or a household disinfectant such as Lysol.
• Don’t store unseasoned firewood on your property.
• Remove any infected trees so the disease can’t spread to others.

If you’re concerned that some of your oak trees have Texas oak wilt, or would like tips on additional ways to prevent it, contact one of our certified arborists at Advanced Tree Care.