Eryngium planum Blue Glitter | Flat Sea Holly

A striking first-year flowering perennial with intense blue, spiky flowers and strong architectural stems – exceptional for cut flowers, dried arrangements and sunny perennial gardens.

Eryngium planum Blue Glitter is a professional-quality Flat Sea Holly selected for cut flower production and perennial gardens. Unlike many traditional perennials, Blue Glitter can flower in the first year from seed without requiring vernalization, making it an especially valuable variety for gardeners and flower growers.

Tall, vigorous plants reach approximately 95 cm and produce numerous distinctive steel-blue to intense blue, spiny flower heads on strong, branching stems. Their unusual texture adds structure and contrast to bouquets and floral arrangements.

Blue Glitter is also remarkably tough in the garden. Once established, plants thrive in sunny, hot and relatively dry conditions, making them an excellent choice for low-maintenance perennial borders and naturalistic planting.

Why You’ll Love Blue Glitter

• Flowers in the first year from seed
• No vernalization required for first-year flowering
• Striking blue, spiny flowers
• Strong, vigorous plants
• Excellent architectural cut flower
• Approximately 95 cm tall
• Long-lasting flowers
• Excellent for fresh and dried arrangements
• Thrives in hot and dry conditions
• Hardy perennial in Zones 4–8
• Excellent for sunny perennial borders
• Attractive to bees and butterflies
• Professional variety for cut flower production

Plant Information

• Botanical Name: Eryngium planum
• Variety: Blue Glitter
• Common Name: Flat Sea Holly
• Plant Type: Perennial
• Special Feature: First-year flowering without vernalization
• Height: approx. 95 cm
• Spring Crop Time: approx. 22–24 weeks
• Exposure: Full sun
• Hardiness Zone: 4–8
• Heat Zone: 12–1
• Seed Form: Raw Seed
• Germination: approx. 7–10 days
• Germination Temperature: 22–24°C
• Sowing: 1–2 seeds per cell
• Uses: Cut flowers, dried flowers, perennial borders, large containers and landscape planting
• Pollinators: Attractive to bees and butterflies

A Perennial That Flowers in the First Year

One of the greatest advantages of Eryngium Blue Glitter is its ability to flower during the first growing season from seed.

Many perennial plants require a cold period before flowering, but Blue Glitter has been bred to flower without vernalization.

For first-year flowering, sow from approximately December to March. Plants can then begin flowering from June through August, depending on sowing time and growing conditions.

Seeds can also be sown in July–August to produce larger, well-established plants that flower the following year.

Exceptional Cut Flower

Blue Glitter is particularly valuable as a professional cut flower.

Its strong stems and distinctive spiny blue flowers provide structure, texture and contrast in floral designs. Unlike softer flowers, Eryngium introduces an architectural element that works beautifully in both modern and natural-style arrangements.

It combines especially well with:

Lisianthus • Zinnias • Snapdragons • Dahlias • Cosmos • Grasses • Achillea • Delphinium • Ornamental foliage

The flowers are naturally long-lasting and can be used in both fresh bouquets and dried floral arrangements.

Excellent for Dried Flowers

Eryngium is also an excellent choice for drying.

The sturdy flower heads retain their distinctive shape and texture after drying, making Blue Glitter valuable for:

• Dried bouquets
• Wreaths
• Seasonal arrangements
• Floral installations
• Everlasting flower designs

For drying, harvest well-developed stems and hang them upside down in a dry, dark and well-ventilated location.

Sowing

For First-Year Flowering

Sow from approximately December to March for flowering plants from June through August.

Sow 1–2 seeds per cell.

Eryngium seeds germinate best with light, so do not cover heavily. Press the seeds gently into the surface or cover only very lightly with fine substrate.

Maintain approximately 22–24°C during germination.

Under suitable conditions, germination normally takes approximately 7–10 days.

After germination, provide plenty of light and grow the young plants at approximately 15–21°C.

For Flowering the Following Year

Seeds can also be sown during July–August.

These plants have more time to develop a strong root system and larger plant structure before flowering the following season.

Growing & Care

Plant Blue Glitter in a sunny position with excellent drainage.

Eryngium performs best in soil that does not remain wet for long periods. A well-drained sandy or loamy soil is particularly suitable.

For best results:

• Choose a position in full sun
• Provide well-drained soil
• Water regularly while young plants establish
• Once established, avoid excessive watering
• Allow the soil to dry somewhat between watering
• Avoid permanently wet or waterlogged soil
• Feed regularly during active growth
• Provide enough space for good air circulation

The ideal soil pH is approximately 6.0–7.5.

Blue Glitter benefits from regular feeding during active growth, particularly when grown for professional cut flower production. In ordinary perennial garden conditions, however, avoid excessively rich conditions that could encourage soft, weak growth.

Thrives in Hot & Dry Conditions

Once established, Blue Glitter is particularly well suited to hot, sunny and relatively dry locations.

Its tolerance of heat and dry conditions makes it an excellent perennial for gardens where more moisture-demanding flowers may struggle during summer.

Good drainage is especially important during winter. Eryngium generally tolerates cold conditions better than cold, permanently wet soil.

Hardy Perennial

Blue Glitter is a true perennial suitable for approximately Hardiness Zones 4–8.

Once established in a suitable location, plants can return year after year, developing into impressive structural plants for perennial borders and cutting gardens.

For the best long-term performance, choose the planting position carefully: full sun and excellent drainage are key.

Valuable for Pollinators

The unusual flowers are not only attractive in floral arrangements – they are also highly appealing to bees and butterflies.

This makes Blue Glitter an excellent choice for combining a productive cutting garden with more pollinator-friendly planting.

Perfect For

• Professional cut flower production
• Cutting gardens
• Fresh bouquets
• Floristry
• Dried flowers
• Dried bouquets and wreaths
• Perennial borders
• Naturalistic gardens
• Gravel and dry gardens
• Large containers
• Pollinator-friendly gardens
• Hot and sunny planting areas

Why Grow Eryngium planum Blue Glitter?

First-year flowering • No vernalization required • Striking blue flowers • Strong 95 cm stems • Professional cut flower • Excellent structural flower for floristry • Fresh and dried use • Heat tolerant • Drought tolerant once established • Hardy perennial • Full sun • Attractive to bees and butterflies

Eryngium planum Blue Glitter is an outstanding choice for gardeners and cut flower growers looking for a long-lasting perennial with distinctive blue flowers and exceptional value for floristry.

Its combination of first-year flowering, strong stems, architectural flower shape, excellent heat and drought tolerance and perennial garden performance makes Blue Glitter especially valuable for cutting gardens, perennial borders, fresh bouquets and dried floral arrangements.