Oak wilt is an infectious tree disease caused by a fungus. Infected trees usually die if they are not treated quickly by a qualified arborist. This can affect aesthetics, decrease property value, and be expensive to manage, all the more so on a community-wide scale. Learning more about what oak wilt is, how to recognize it, and what to do about it is the first step towards keeping our neighborhood’s trees safer.
Oak wilt spreads both above and below ground. The most characteristic symptom of oak wilt is yellow and brown leaf veins in live oaks known as veinal necrosis. Fungal mats develop under the bark on the trunks and major branches of infected red oak trees. When the fungal mat enlarges and cracks the bark of the tree, an odor is released that attracts sap-feeding beetles. The fungus is transmitted when these beetles feed on the fungal mats and carry fungal spores to fresh wounds or cuts on healthy oak trees. Because oak trees have interconnected roots, the disease can be spread below ground through grafted root systems, eventually killing increasing numbers of oak trees in the area.
To help curb the spread of oak wilt, arborists recommend the following:
• Avoid pruning oak trees from February 1 to June 30. (Below, find a proposed pruning schedule provided by Texas Oak Wilt.)
• Make proper pruning cuts.
• Paint all oak wounds/cuts immediately with any type of paint.
• Sterilize tools with 10% bleach between trees.
• Only move firewood that has dried for over one year
For more information on oak wilt, visit https://texasoakwilt.org/community-tools/materials for plenty of information and tips. For those dealing with oak wilt head-on, the Texas Forest Service offers a listing of certified arborists at https://texasoakwilt.org/vendors, though they cannot endorse or recommend any specific vendors.