The West Lake Hills and Rollingwood city councils are considering options to protect their cities’ oak trees from oak wilt—a fungal disease that kills up to 90 percent of untreated oak trees, said Eric Beckers, Texas A&M Forest Service project forester. The disease is spread primarily underground through interconnected roots, he said.
“This beast here is insidious—it doesn’t just stop,” Beckers said of oak wilt. “Whenever we can, we try to contain this disease.”
Although both West Lake Hills and Rollingwood have oak wilt disease centers, the region of greatest concern is a disease center in unincorporated Travis County that may cross over from the Westwood Terrace area into West Lake Hills as early as next year, he said.
“Live oaks have enormous root systems, so [oak wilt] is hard to contain in Texas, as opposed to areas that have mostly red oaks,” Beckers said.
Solutions
Trenching to sever the roots of infected trees is the best option to stop the spread of oak wilt, Beckers said. Injecting trees with fungicide can also improve the survival rate of susceptible trees, he said.
“It takes a while for [oak wilt] symptoms to develop,” Beckers said. “That’s why we put our trench 100 feet [beyond trees that are showing signs of infection]. We pass up green trees that are probably already infected.”
West Lake Hills responds
West Lake Hills City Council discussed the possibility of implementing a 2,000-foot-long trench along Westwood Terrace to stop the disease from spreading to Las Brisas Street during its Jan. 13 meeting.
The proposed trench would mostly fall in unincorporated Travis County, Beckers said.
Travis County officials will allow the trench, but the cost would fall on West Lake Hills, Mayor Linda Anthony said.
“If we decide to trench, there is a chance [Travis County Water Control and Improvement District 10] will share the cost because they may put a new water line in on Westwood [Terrace],” she said. “[The project] is quite expensive.”
WCID 10 provides water and wastewater service to the district that includes West Lake Hills.
On Jan. 27, West Lake Hills City Council unanimously approved committing $15,000 to create a survey and documents confirming a proposed location for a trench.
“[Trenching] is an expensive item but it seems to be the only way to contain [oak wilt],” Anthony said. “Everything says [oak wilt] is coming, and by the time it gets here, it will be too late [for treatment].”
Council members also agreed Jan. 27 to add an oak wilt fee to some residential and commercial permits.
Rollingwood reacts
At its Dec. 16 meeting, Rollingwood City Council discussed amending the city’s tree permit requirements to prevent overland spread of the disease to the area in light of the oak wilt threat in West Lake Hills.
Beetle flies carrying oak wilt from the infected red oaks to injured or recently pruned live oaks can start new disease centers, Beckers said. Contaminated tree-trimming tools and firewood can also bring beetle flies harboring oak wilt to a new area, he said.
Rollingwood may consider measures to deter the spread of the disease, such as requiring residents to choose from a list of preferred tree trimmers who have been trained in oak wilt measures, City Administrator Charles Winfield said.
Education
“Educated arborist communities are extremely important,” Beckers said. “Some communities have arborists sign an agreement that they understand they must paint wounds [with tree sealant]on oaks [to deter beetle flies].”
Residents should examine their trees in May and June to look for signs of illness such as dropping leaves, he said.
“We can’t grow trees overnight—we try to protect what we have,” Beckers said. “New people move to the area every day. We need to educate our neighbors on preventive measures.”
Additional reporting by Leslee Bassman
