Ask a Consulting Arborist Q&A: Tree Health

Q: What's the cause of a burr oak's leaves all turning brown in July?

Thursday, September 22, 2016  

Q: I have a large burr oak tree where all the tree leaves completely turned brown at the same time and have not fallen off. This occurred in late July in Texas. The small branches appear to be brittle. There are signs of new growth on the main trunks. What could be the problem?

A: The answer to this question is difficult without knowing more about the tree. If it was a recently planted tree, say two years or less, the symptoms could apply to a tree that had undergone moisture stress and then received a good dose of moisture that promoted new growth on the wood that was not yet dead. Since you say it is a large tree, and I assume it is a well-established, mature tree, I suspect that there had been an occurrence of too much or too little moisture. This year has been a pretty good year for moisture in Texas, so it is unlikely that a mature tree would display these symptoms for that reason. I suspect some type of problem with the root system, such as excavation or radical change in the soil profile from grading or filling.

An experienced ISA Certified Arborist or ASCA Consulting Arborist should be
consulted on site to get a better indication of what the problem might be.

Responder: Robert Hager, RCA, #523, San Marcos, TX