Ask Mr. Smarty Plants

Nandina domestica is a suckering shrub in the Berberidaceae (Barberry) family that is a native of China and Japan, and therefore not in our range of expertise at the Lady Bird Johnson Wildflower Center. It is, in fact, considered an invasive species, especially in the South. This Floridata site, Nandina domestica, can give you more information but also advises that it is considered a Class I invasive species by the Florida Exotic Pest Plant Council. We understand that some cultivars turn that bright red in the Fall, and that it is considered normal.

Petrea volubilis (Queen's wreath) is also non-native to North America and therefore we have no information on it in our Native Plant Database.  It is a tropical which originated in the Caribbean, and probably grows best in USDA Hardiness Zones 10 to 11. Williamson County is approximately Zones 8a to 8b, and that may have caused the problem with your plant. The Lady Bird Johnson Wildflower Center is dedicated to the growth and protection of plants native not only to North America but to the area in which they are being grown. Native plants will be accustomed to the climate, rainfall and temperatures of that area and will need less water, fertilizer and maintenance.