Ask Mr. Smarty Plants

It sounds like you were already on the right track when you wrote to us initially. As we mentioned in our first response, there are a lot of things that can be causing the strange coloration in your live oak leaves. We don't believe water lack would cause anything but brown leaves, but who knows? This is really the sort of thing that needs eyeballs on the tree and someone who knows what they are talking about. Since our answers are read by many people we try to put in an explanation for why we recommend native plants or certain practices, such as not planting a Bradford pear, in all our answers. We will say a sprinkler system is not the ideal for watering trees. Usually, especially for recently planted trees, we recommend getting a hose down in the soil around the roots and letting it dribble until water is on the surface, and doing this two or three times a week, especially in hot, dry weather.

We are neither plant pathologists nor entomologists and have to rely on research and experience to help other gardeners. One thing we did not mention previously was the possibility that an herbicide has been used in the vicinity of the tree recently. Even weed and feed lawn fertilizers can cause problems, especially for a young tree. The herbicide in those fertilizers is for broad leaf weeds in the lawn and guess what? A tree is a broad leaf plant, too. The gardener really has to be a detective, and all we can do is suggest some of the things to consider.

By the way, just one last word. Who told you that Pistacia chinensis, Chinese pistache was a native to Texas? Read this Dave's Garden forum on the plant for some comments on its invasiveness. It originated in (guess where?) China. Here is an article from Texas Invasives.org on the problems this tree can cause.