SAN ANTONIO \u2013 In South Central Texas, oak trees aren\u2019t just trees: they\u2019re infrastructure, history and climate protection. <\/p>\n
Between February and June, those trees face an increased risk from oak wilt, a fast-moving disease that can spread quickly and kill entire clusters of oaks. The disease that impacts oak trees across much of the region. <\/p>\n
According to the Texas A&M Forest Service, the disease has been reported in more than 75 counties, with heavy impacts in the Hill Country.<\/p>\n
Oak wilt cases have been identified in parts of Bexar County, including Helotes, Leon Valley, Shavano Park, Hollywood Park and Castle Hills.<\/p>\n
How oak wilt impacts trees<\/p>\n
\u201cOak wilt is a very devastating disease in Central Texas,\u201d said Demian Gomez with the Texas A&M Forest Service. \u201cIt\u2019s fungus that infects every single oak tree that it encounters.\u201d<\/p>\n
All oak species are affected, but some are more vulnerable than others:<\/p>\n
Red oaks have nearly a 100% mortality rateLive oaks often die, especially when the disease spreads undergroundWhite oaks may be less susceptible but can become infectedHow oak wilt spreadsVia connected root systems, where nearby oak trees share underground connectionsVia sap beetles, which carry fungal spores from infected trees to healthy ones<\/p>\n
These beetles are attracted to fresh wounds on oak trees, especially during spring and early summer.<\/p>\n
\u201cWhen you prune, that wound is going to release chemicals that basically attract these beetles,\u201d Gomez said. <\/p>\n
Experts recommend not pruning oak trees between February and June, when beetle activity and fungal spread are at their highest.<\/p>\n
What to look for in infected treesBrown or dark veins on live oak leavesTip burn where the ends of leaves turn brownFungal mats under the bark in severe cases, especially in red oaks<\/p>\n
Due to other issues such as drought or herbicide exposure can cause similar symptoms, experts said proper identification is important before taking action.<\/p>\n
What to do if you suspect oak wilt<\/p>\n
If pruning is unavoidable for safety reasons, experts recommend painting the wound immediately.<\/p>\n
\u201cAny type of paint or pruning seal works,\u201d Gomez said. \u201cIt creates a barrier that keeps insects from introducing the fungus.\u201d<\/p>\n