Plus, their tendency to bloom through fall and winter in their preferred growing zone (7a through 9b) means they'll be less likely to compete for resources during the height of gardenia's blooming ...

Gardenias can be grown in USDA Plant Hardiness Zones 8-11, with a number of varieties cold hardy enough to survive in Zone 7. But the shrubs can suffer from winter damage when the temperature dips ...

Texas has eight plant hardiness zones, ranging from the cold-hardy northwestern Panhandle to the warmer southern regions.