Perennial Metallic Blue Flowers Alpine Sea Holly Seeds for Cutting – Eryngium alpinum

Description Alpine Sea Holly Seeds Eryngium alpinum – Metallic blue, thistle-like blooms with spiny silver bracts, perfect for cutting & drying Stunning perennial producing steely-blue flower heads surrounded by a ruff of silvery, spiky bracts. Adds dramatic texture and cool color to borders, gravel gardens, and cutting beds. Long-lasting flowers are ideal for both fresh bouquets and dried arrangements, and they attract bees and butterflies. Common Name: Alpine Sea Holly, Blue Sea Holly Latin Name: Eryngium alpinum Plant Height: 60–90 cm (24–36 in) Seeds per Gram: ≈ 500–700 seeds/gram Life Cycle: Perennial (hardy, blooms second year) Available Color: Metallic blue with silver bracts Non-GMO · Open-pollinated · Perennial · Exceptional for dried flower crafts Botanical & Variety Details Common name(s)Alpine Sea Holly, Blue Sea Holly, Eryngium alpinum Latin nameEryngium alpinum – classic cut-flower and dried-flower selection Mature height60–90 cm (24–36″) — sturdy, branching stems with spiky flower heads Seeds per gram~500–700 seeds/gram (approx. 14,000–20,000 seeds/oz) Growth cyclePerennial — hardy, often blooms in the second year, long-lived clump Ornamental periodMid-summer to early autumn (flowers hold color for weeks, then mature to attractive seed heads) Unique trait Metallic blue blooms · Spiny silver bracts · Excellent pollinator plant · Superb for fresh and dried arrangements �� Planting & Growing Guide �� Best planting seasonLate spring to early summer; cold stratification improves germination. Can also be sown in autumn to overwinter naturally. ��️ Ideal temperature60–70°F (16–21°C) for germination; mature plants hardy down to -30°F (-34°C) ☀️ Shade requirementFull sun is essential (minimum 6 hours of direct sun). Intense light ensures the strongest blue color and upright stems. Very light shade tolerated but reduces flower quality. �� Sowing rate (per m²)0.5–1 gram per square meter (approx. 250–700 seeds/m²) for a naturalistic or cutting garden display. �� Sowing depth1/8 inch (3 mm) — light cover with fine soil or vermiculite; seeds need light to germinate. �� Water & careKeep evenly moist until germination (14–30 days, slow). Well-drained, even gritty, soil is essential. Drought tolerant once established. �� Spacing after thinningThin or transplant to 12–18 inches (30–45 cm) apart to allow good air circulation and prevent flopping. �� Days to bloomApprox. 120–180 days from sowing; typically blooms in second year from a spring sowing. Early indoor starts may bloom first year. Sun requirement: Full sun is crucial for intense metallic blue color and sturdy, upright stems. In partial shade, plants often become leggy and the blue fades to grayish-green. Provide afternoon protection only in extremely hot, arid climates. Pro density tip: For cutting gardens aiming for long, straight stems, sow 1 g/m² and thin to 35–40 cm. For massed borders or gravel gardens, sow 0.5 g/m². Cold-moist stratify seeds for 3–4 weeks before sowing to significantly boost germination rates. Sowing quick guide: Spring · Full sun · 0.5–1 g/m² · Cover 1/8″ deep Germination 60–70°F | Full sun essential for rich blue color Harvest when flower heads are fully colored and firm for the longest vase life (7–14 days) or air-dry them upside down for everlasting arrangements. Deer resistant · Excellent for pollinator gardens, contemporary bouquets, and dried flower crafts.