Ask Mr. Smarty Plants

There are five members of the genus Cercis listed in our Native Plant Database, or which Cercis canadensis var. texensis (Texas redbud) seems most likely to be the one growing in Burnet County. This USDA Plant Profile Map shows it growing in Travis County, right next to Burnet County and obviously it grows in Burnet County as well, it just hasn't been reported doing so. We always try to ascertain if a plant is native to the area in which it is being grown. Follow this liink Cercis canadensis var. texensis (Texas redbud) to our webpage on it and note these growing conditions:

"Growing Conditions

Water Use: Low , Medium
Light Requirement: Sun , Part Shade
Soil Moisture: Dry
Soil pH: Alkaline (pH>7.2)
CaCO3 Tolerance: Low
Drought Tolerance: Medium , High
Cold Tolerant: yes
Heat Tolerant: yes
Soil Description: Well-drained, calcareous, rocky, sandy, loamy, or clay soils, usually limestone-based.
Conditions Comments: Drought- and cold-tolerant within its range. Give dappled shade when young. A selection called Sanderson is said to be the most drought-adapted Texas redbud cultivar."

Sounds like it belongs right where you are growing it, but if the sun exposure or water amounts in the soil are different in your garden, that could be causing some of the problem. So, let's look around for some other explanations for your problem.

Here is a previous Mr. Smarty Plants answer on drought stress to redbuds. After the kind of year Central Texas has had, there is almost undoubtdly drought stress. The redbud still does not need to be flooded with water, but watering once a week by pushing the hose down in the soil and letting it drip until it comes to the surface will help get water down to the roots where it is needed the worst.

From Ask.com Caring for Redbud Trees

From Top Turf, we found this website Insect Damage with some good pictures of insects and the damage they do to leaves. 

In the final analysis, we are gardeners, not plant pathologists. We are sure you realize that in the very difficult weather conditions we have been having the last couple years with drought and record heat as well as record cold, conditions are probably not normal. Insects that might ordinarily not disturb you could be forced to invade your trees. The trees could themselves be demonstrating stress. The people at the Burnet County Extension Office are more likely to have up to the minute information on what is damaging plants in the area, as well as something to do about it. The website we have linked you to has contact information, and may, indeed, have information on the site itself on what is disturbing your trees this season.