Ask Mr. Smarty Plants

Esperanza is one of the common names of  Tecoma stans (Yellow bells). Since you called it that, we are thinking that perhaps you purchased it from a nursery that did not specialize in native plants. From our webpage on that plant (which you can read in full by following the weblink above):

"Conditions Comments: North American native varieties of this species can survive winters within their natural range but may die to the ground during especially harsh winters even there. Varieties sold in nurseries may be from tropical stock and not do so well in US cold. Yellow bells is drought tolerant and Southwestern varieties are adapted to monsoon rains with dry spells between. They may flower better if such conditions are emulated in planned landscapes, so allow ground to dry out between waterings. It is tolerant of confinement if containers are at least 12 inches in diameter and thus makes a good potted specimen."

As you can see from this USDA Plant Profile Map for Tecoma stans (Yellow bells), it does not grow natively in Tom Green County, TX. Since it is a drought tolerant plant that prefers dry soil, we would not recommend putting extra water on the roots. However, spreading a good quality mulch on the root area (without touching the trunk) will help to protect the roots against cold. As mentioned above, this plant may die to the ground in a harsh winter, but if the roots are protected, the whole tree has a better chance of survival.