And it should be remembered that, even in cases, where a white oak survives an attack of oak wilt, the tree can remain a host for the fungus and give it a base from which to spread. Texas live oak US Forest Service Leaf damage is the earliest indication of oak wilt. Leaves of infected trees begin to lose their green color, dulling and then browning or yellowing from the outer edges inward. As the disease advances, leaves begin to drop, sometimes while still green, starting from the ends of the branches. The speed of the progression of the disease depends upon the species of tree infected.
Red oaks can die from oak wilt in as short a time as a month.
Texas live oaks may survive as long as six months. White oaks may survive as long as several years after infection. In a small number of instances, Texas live oaks and white oaks appear to have survived oak wilt infection. However, it would be unwise to depend on this. In red oaks, a fungal mat may appear when large masses of fungal tissue break the bark.