Oak wilt is a deadly fungal disease that threatens our oak trees, and it’s quickly spreading throughout San Antonio and Texas.
The fungus invades an oak tree’s roots, choking off its water. It’s spread by sap beetles, untreated firewood cut from an infected tree, and contaminated tree-trimming equipment — which should have been disinfected after trimming a tree with oak wilt, but wasn’t.
The fungus has reached Whispering Oaks, a neighborhood in District 9, which I represent on City Council. According to Mark Duff, an oak-wilt expert with the Texas A&M Forest Service, the fungus has already hit eight areas in Bexar County.
To see the impact oak wilt has on a neighborhood, just drive through a particular corner of the City of Hollywood Park. You’ll see entire blocks of houses with dried-up, gray oak trees in their front yards.
Where the oaks with green leaves start up again, that’s oak wilt’s line of demarcation. Those healthy trees are next. The fungus acts fast, and can kill an oak tree in a matter of weeks.
Hollywood Park is one of many communities impacted by oak wilt in Central and South Texas. It has been spreading south toward San Antonio for years, and now it’s here.
Imagine your yard with trees killed by this fungus. What does that do to your pride in your property? What does that do to your property value?
I’ve heard one estimate that a mature oak tree adds roughly $25,000 to a property’s value.
Last week, City Council received its first briefing on oak wilt. I requested the session to highlight a problem that threatens oak trees across San Antonio — to create an appropriate sense of urgency.
The City of San Antonio must develop an aggressive and effective strategy to slow oak wilt’s progress. At the moment, we don’t have such a plan.
We also have to be realistic — treatment of this disease is hit-and-miss, and prevention is difficult. But we must make the effort.
I believe the City’s should immediately take the following steps:
- Discontinue City brush collection from Feb. 1 through July 1 in neighborhoods affected by oak wilt. Springtime is the period when fungal mats are most likely to form on oaks and sap beetles are most active. Experts agree: avoid tree trimming in that time period.
- Study other cities’ responses to oak-wilt infestation. In Texas, these include Austin, Dallas, Fort Worth, Houston, Lubbock, and Midland.
- Initiate a strong public-awareness campaign on the dangers of oak wilt and treatment methods. This information, for example, could be included in monthly CPS Energy and SAWS bills.
- Work closely with the Texas A&M Forest Service, and partner with Bexar County.
Oak wilt poses a huge threat to San Antonio’s tree canopy. Currently, we’re not sufficiently prepared to meet it.

*Top Image: An oak tree that has been infected stands alone near healthy trees. Photo by Scott Ball.
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