Oak wilt is a fungal disease that spreads from sap-feeding beetles attracted to fresh wounds on oak trees. These wounds can be caused by broken limbs, root systems, or from pruning.
You can protect your trees by avoiding damage caused by lawn equipment such as weed-eaters, lawn mowers, and shovels. Prune your oaks only at the coldest times of the year when the activity of the disease carrying beetle is at its lowest. You should also paint all cuts or damaged areas with pruning sealer paint as soon as any cuts are made, and sterilize all pruning equipment between trees. It is important to note that even firewood is susceptible and will create a breeding ground the beetles can spread from, so make sure to cover your oak firewood with plastic and seal the edges.