Sea Holly 'Blue Glitter'

Sea Holly (Eryngium / Plains Eryngo)

Striking and sculptural, Sea Holly (Eryngium) brings a silvery, metallic sheen to garden beds and bouquets. Its spiky, thistle-like blooms shimmer in shades of steel blue and icy lavender, framed by delicate bracts that glow in the sun. Also known as Plains Eryngo or Flat Sea Holly, this hardy perennial thrives in heat and poor soil, asking little and giving much. With sturdy stems and a strong architectural presence, it offers lasting beauty in fresh arrangements and dries to perfection. Flowers typically appear in the second year, returning reliably in Zones 3–8. A favourite among bees and beneficial insects, Sea Holly lends wild elegance and a touch of the untamed to every garden.

DETAILS:

QTY: 50

TYPE: Perennial

SITE: Full Sun

DEPTH: 1/8"

GERMINATION: 7-10 days at 22-24°C

HEIGHT: 40 - 46"

MATURITY: 365 Days

SPACING: 18-24”

PINCH: No

Transplant (recommended): Sow seeds 10–16 weeks before your average last frost date. Do not cover the seeds with soil, as light is required for germination. To avoid burying the seeds, bottom water or mist lightly. Germination can be slow and erratic. Once seedlings have emerged (5-8 weeks after sowing), transplant them into cell packs or 2–4" containers. Maintain a growing temperature of 13°C–16°C and avoid temperatures above 21°C. Harden off seedlings for 7-10 days before transplanting them outdoors after all danger of frost has passed.

Direct Seeding (alternative): Due to its taproot, Eryngium can also be direct-sown. Sow seeds in late fall for spring germination, or in early spring. Surface sow and gently press seeds into the soil, keeping the area consistently moist until germination.

Soil Preference and Watering: Eryngium thrives in full sun and requires well-drained, lean, or sandy soil. It will not tolerate heavy, wet soils. While establishing, keep the soil consistently moist. Once mature, it is extremely drought-tolerant and prefers to be on the dry side.

Pinching and Fertilizing: Pinching is not typically necessary for Eryngium. Deadheading spent flowers may encourage a small second flush of blooms, depending on the species. Fertilizing is not required and can lead to weak, leggy growth.