Flourishing in sunny, well-drained sites such as rock gardens and wall plantings, this charming little skullcap produces spikes of bright blue, white-lipped flowers through much of summer on tidy 10-inch plants. It's used as a medicinal plant in East Asia. Zone 4. Propagated from seed. Deep 3.5-inch pots. Photo: Kor!An (Андрей Корзун), licensed under CC BY-SA 3.0