ALL OAKS ARE SUSCEPTIBLE TO OAK WILT!
Generally, all oak trees are placed in one of two groups – red oaks or white oaks. Red oaks are the most susceptible to oak wilt and they will typically die within two to four weeks of symptom appearance. Common red oaks that are extremely susceptible to oak wilt include Spanish oak (Quercus buckleyi), Shumard oak (Q. shumardii), blackjack oak (Q. marilandica), and others.
Oaks in the white oak group are the least susceptible and tend to resist the disease. Very few white oaks have been identified with oak wilt in Texas. Even if a white oak contracts the disease, the tree will generally survive with little noticeable impact. Common white oaks include post oak (Q. stellata), bur oak (Q. macrocarpa), chinkapin oak (Q. muehlenbergii), and others.
Interestingly, live oaks are somewhat intermediate between the two groups of oaks but are very susceptible to the disease. Live oak is probably the most common oak tree in Central Texas and they succumb to oak wilt in the greatest numbers. Live oaks commonly form root sprouts which allow a number of trees to share a common root system. A tight group or grove of these trees is often called a live oak mott. If oak wilt infects one of the trees in the mott, the disease quickly spreads through the common root system to adjacent trees and an oak wilt infection center begins to develop.