While central Texas sees hot and humid summers, north Texas gardeners must face cold, dry winters. The state lies in U.S. Department of Agriculture (USDA) Hardiness Zones 6 to 9. Texas gardeners should select a tree according to the USDA zones as well as the tree's flower color, bloom time and general culture. Various purple flowering trees perform well in Texas home gardens. Texas Redbud The Texas redbud tree (Cercis canadensis var. texensis) belongs to the pea family (Fabaceae) and thrives in the foothills and canyons of north central Texas.