Post Oaks and Hot Weather

In the summertime when the weather is hot…

Mungo Jerry, “In the SummerTime”

I was 16 when Mungo Jerry’s song, “In the Summertime” came out in 1970. What a great summer. I drove a combine that summer harvesting wheat from the Texas Panhandle to Nebraska and that song played on the AM radio all summer.

Unfortunately, the summer heat can cause severe stress on Post Oaks with root systems that have been damaged. Usually, we humans are the cause through construction activities and over watering of our turf lawns. Post Oaks are very tough trees, but when their root systems are compromised, they don’t recover well and often succumb to the summer heat.

From September 2018 through June of 2019, North Texas experienced abundant and regular rain. Far more than we normally receive. Any Post Oak that is in an area that is on the downhill side of drainage (especially off house roof tops), is subject to root system dieback due to the excess water. Tree Shepherds personnel are encountering many, many Post Oaks this summer that are severely stressed and dying and most of these are in areas of poor drainage.

There is little that can be done to correct the problem once the symptoms are noticed. When the symptoms appear, it indicates that the tree is drying out. When the tree hits the tipping point, the decline can be very rapid, and a tree can go from green to brown in a week or less.

The tree on the left is showing symptoms of water stress. The immediate treatment for a tree in this state is to reduce the crown as much as possible to reduce the demand on the root system. Tree Shepherds can do this crown reduction without destroying the canopy or the looks of the tree. Approximately 25% of the canopy is removed in this process.

The two trees in the picture are dead and dying. When the tree is completely brown, it is gone. The tree on the right is drying out and probably not saveable.

If a crown reduction helps the tree survive the summer, then there are some treatments that we will recommend to help the trees recover their root systems. But, the tree has to make it through the summer before we would recommend spending money on those treatments. The crown reduction is the immediate treatment to help the tree through the summer.

Give us a call at 972-317-9598 if you have a Post Oak showing these symptoms of summer heat stress.

Scott Geer

Scott Geer

Scott Geer has a master's degree in forestry from Stephen F. Austin State University and is an ISA Board Certified Master Arborist.® He is also a graduate of the American Society of Consulting Arborists Academy.