Oak wilt is one of the most destructive tree diseases in the United States, and it is killing oak trees in central Texas at epidemic proportions. Oak wilt is an infectious disease caused by a fungus which invades and disables the water-conducting system in susceptible trees. All oaks can be infected with oak wilt, but some species of oak are more susceptible than others. It can be a problem wherever live oaks tend to be the predominate tree. It does not matter whether they are transplanted or naturally grown. An individual tree’s age, size or previous health status does not make it more or less likely to contract or die from oak wilt. Also, if one tree in a group of live oak trees becomes infected with oak wilt, the pathogen can spread through the common root system at an average rate of about 75 feet per year.
Live oak trees infected with oak wilt usually die within two to four months.The leaves will fall from the tree and dead leaves with brown veins can be found on the ground under the tree. Adjacent trees begin to drop their leaves and die a few months later as the disease progresses from tree to tree through the interconnected root system.
Because oak wilt is such a devastating disease, prevention is the key. This is especially true since once a tree is exposed to the disease, there is very little that can be done to prevent its demise. Perhaps one of the easiest means of the prevention of oak wilt transmission is through the proper cleaning of pruning tools.
When trimming and pruning, you should always be mindful of the potential for disease transmission and therefore there are a few preventative methods that we suggest you do.
1. Always sanitize your tools with 70% isopropyl (rubbing) alcohol between site and/or trees.
2. Immediately paint all wounds on oaks to prevent contact with contaminated beetles. Wounds should be painted regardless of the time of year they were made with commercial tree wound sealant.