Nigella damascena comes from the Mediterranean and has been grown in cottage gardens for centuries, yet it never feels tired. The flowers — most often a clear, slightly steely blue, though white and pink forms exist — are cradled within a ruff of thread-like bracts that give the plant its common name. At one to two and a half feet tall, it weaves through its neighbors with an airy self-sufficiency.

Sow directly into the ground as soon as it can be worked in spring; Nigella resents transplanting and prefers to find its own place. In cooler summer climates, successive sowings every three to four weeks extend the display well into midsummer. After the petals drop, the inflated, striped seed pods take over — equally beautiful and indispensable for dried arrangements.