25 Seeds Blue Star Sea Holly Eryngium planum

Blue Star Sea Holly is a striking perennial known for its branched, steel-blue flower heads and spiny, thistle-like bracts that add unique texture and color to garden beds and borders. Its cool-toned blooms contrast beautifully with warm-colored flowers and remain visually interesting well after they fade, making it a favorite for both fresh and dried arrangements.

This hardy perennial thrives in full sun and well-drained soil, performing best in leaner conditions where it develops strong stems and abundant blooms. The flowers are excellent for cutting and hold their color when dried, while the architectural foliage provides season-long structure in mixed borders, pollinator gardens, and low-water plantings.
Species: Eryngium planum
Variety: Blue Star
Type: Perennial
Plant_Habit: Upright, clump-forming
Sun: Full sun
Soil: Well-drained, sandy or gravelly, low fertility
Days_to_Harvest: Not applicable
Zones: 5-9
Germination: 14-30 days with cold stratification
Sowing: Surface sow, press into soil, do not cover deeply
Spacing: 12-18 inches
Notes: Drought tolerant once established; stems hold color well when dried