The name comes from the Greek word for dolphin — delphis — a reference to the curved silhouette of the flower bud that botanists noticed centuries ago. Delphinium encompasses more than 500 species ranging across temperate and subtropical regions of North America, Europe, Africa, and Asia, from annual roadside wildflowers to the stately perennial hybrids of English cottage gardens. As a genus, it belongs to the buttercup family (Ranunculaceae) and includes plants of genuinely different temperaments: some ephemeral and easy, others exacting and short-lived.

The garden hybrids are demanding by nature — they want fertile, moist but well-drained soil, full sun, cool summers, and staking against wind and rain. Spent flowers cut back to the basal leaves will often produce a second flush in late summer. Humid climates south of zone 7 can be a real challenge; in those conditions afternoon shade and excellent air circulation become important. Despite their care requirements, few plants produce a blue of comparable depth, and that quality — plus the reliable interest of hummingbirds and butterflies — keeps them in the garden repertoire.