As June arrives, this uncommon beauty begins its show of tubular, curved, 1½ inch lavender-blue flowers, which resemble those of Penstemon. The flowers appear in clusters at the tops of each stem and by midsummer, the plant is practically covered in blooms continuing until fall. It's a fast growing evergreen perennial with attractive, deep green leaves along upright, green stems and grows to 3 feet tall and 5 feet wide, forming a dense bushy mound. It may be pruned back after flowering to keep it compact. It needs part shade, average moisture, and rich soil. In the right conditions, it's a long-lived plant and is able to withstand some amount of frost. Native to the subtropical forests of the Himalayas. USDA zones 8 - 11.