Salvia sclarea v turkestanica - Clary Sage
This vigorous architectural Sage has been grown in almost every botanical sanctuary in human history. Its uses are considerable: a flavoring for wines, an oil for perfumes, potpourri and incense. Medicinally, it's supposed to ease stomach ailments and stop aging.
Most importantly, it's gorgeous and thrives on total neglect. In full sun, with almost no water, the large, gray-green leaves remain attractive all season long. Each stem is topped with a profusion of lilac-white blossoms and brilliant white bracts, very showy from May to September.
Clary Sage is hardy in zones 6 - 10. Drought tolerant, deer-proof. It reseeds generously. Once planted, it will always grace your garden.