Heirloom

Blue Glitter

Eryngium planum

Photo: AnRo0002 · Wikimedia Commons · (CC0)

Attractive blooms with a metallic shine. Eryngium is a hardy perennial with long, sturdy stems. Tolerates hot, sunny locations. Plants produce flowers during the second year of growth and in subsequent years. Attracts bees, beneficial flies and wasps. Also known as plains eryngo and flat sea holly. Perennial in Zones 3-8. FleuroSelect Gold Award Winner.

Harvest

365d

Days to harvest

📅

Sun

Full sun

☀️

Zones

5–9

USDA hardiness

🗺️

Height

2-3 feet

📏

Planting Timeline

Zone:

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Start Indoors

Transplant

Direct Sow

Start Indoors

Transplant

Direct Sow

Showing dates for Blue Glitter in USDA Zone 7

All Zone 7 flower →

Zone Map

Click a state to update dates

Blue Glitter · Zones 5–9

What grows well in Zone 7? →

Growing Details

Difficulty

Easy

SeasonPerennial

ColorMetallic blue

Zone-by-Zone Planting Calendar

Zone	Indoor Start	Transplant	Direct Sow	Harvest
Zone 3	April – May	June – July	June – August	—
Zone 4	March – April	June – June	June – July	—
Zone 5	March – April	May – June	May – July	—
Zone 6	March – April	May – June	May – July	—
Zone 7	February – March	April – May	April – June	—
Zone 8	February – March	April – May	April – June	—
Zone 9	January – February	March – April	March – May	—
Zone 10	January – January	February – March	February – April	—
Zone 1	May – June	July – August	July – September	—
Zone 2	April – May	June – July	June – August	—
Zone 11	January – January	January – February	January – March	—
Zone 12	January – January	January – February	January – March	—
Zone 13	January – January	January – February	January – March	—

Complete Growing Guide

Light: Full sun (6 or more hours of direct sunlight a day). Soil: Loam (Silt), Sand. Soil pH: Acid (<6.0), Alkaline (>8.0), Neutral (6.0-8.0). Drainage: Good Drainage, Occasionally Dry, Very Dry. Height: 2 ft. 0 in. - 3 ft. 0 in.. Spread: 1 ft. 0 in. - 2 ft. 0 in.. Spacing: 12 inches-3 feet. Maintenance: Low. Propagation: Division, Seed. Regions: Coastal, Mountains, Piedmont.

Harvesting

Type: Schizocarp.

Storage & Preservation

Blue Glitter flowers are best stored fresh in a cool location with indirect light. Cut stems should be placed immediately in cool water (40-50°F) to extend vase life to 2-3 weeks. Keep away from ripening fruit and direct sunlight to preserve the metallic sheen. For preservation, air-dry stems in bunches hung upside down in a dark, well-ventilated space for 2-3 weeks to create long-lasting dried arrangements. Alternatively, press individual flower heads between parchment paper under weight for 4-6 weeks for botanical crafts. Freeze-drying is also effective for preserving the structure and color.

History & Origin

Origin: E. Central Europe to Mongolia and W. Himalaya

Advantages

+Attracts: Bees, Butterflies, Pollinators
+Low maintenance

Companion Plants

The flowering neighbors in our database — Marigolds, Calendula, Zinnia, and Cosmos — pull their weight next to Blue Glitter by drawing parasitic wasps and hoverflies that knock back aphid and thrips pressure. Alyssum runs the same play at ground level, and in our zone 7 Georgia gardens it stays in bloom long enough to overlap with Eryngium's midsummer peak. Lavender pairs best structurally: both plants want the same dry, full-sun conditions and neither will crowd the other's roots or compete for water. Nasturtiums act as a trap crop, pulling aphids off the Eryngium and onto themselves.

Black Walnut is a hard no — the tree produces juglone from its root system, and even shallow-rooted plants 30–40 feet out can show dieback. Fennel is allelopathic to a wide range of species and is better given its own isolated corner entirely. Eucalyptus releases growth-inhibiting compounds as its leaf litter breaks down; not a plant most Georgia gardeners are dealing with, but if one's on your property, keep Blue Glitter well clear of the drip line.

Plant Together

Marigolds

Repel aphids, whiteflies, and nematodes while attracting beneficial insects

Alyssum

Attracts beneficial insects like lacewings and provides ground cover

Nasturtiums

Act as trap crops for aphids and cucumber beetles

Lavender

Repels moths, fleas, and mosquitoes with its strong fragrance

Petunias

Deter aphids, tomato hornworms, and other garden pests

Zinnia

Attract beneficial pollinators and predatory insects

Cosmos

Attract beneficial insects and provide structural support

Calendula

Repel aphids, whiteflies, and attract beneficial predatory insects

Keep Apart

Black Walnut

Produces juglone which is toxic to many flowering plants

Eucalyptus

Releases allelopathic compounds that inhibit growth of nearby plants

Fennel

Inhibits growth of most garden plants through allelopathy

Troubleshooting Blue Glitter

What you'll see, why it happens, and what to do about it.

Crown rotting at soil level, plant wilting and collapsing despite adequate water

Likely Causes

Crown rot (Phytophthora or Pythium spp.) from poorly drained soil holding moisture against the base
Heavy clay soil that stays waterlogged after rain

What to Do

1.Dig the plant, trim away blackened root tissue with a clean knife, and replant in a raised bed or berm with gritty, well-draining soil
2.Work coarse sand or pea gravel into the planting hole — Blue Glitter is native to dry, rocky European plains and genuinely does not want wet feet
3.Don't mulch right up against the crown; keep 2–3 inches clear

Leaves going pale green to yellow overall, plant growing slowly in its first season

Likely Causes

Nitrogen deficiency in very lean or sandy soil — ironic, since Eryngium prefers poor soil, but 'poor' doesn't mean totally depleted
Root disturbance from transplanting a taproot that doesn't appreciate being moved

What to Do

1.Side-dress with a thin layer of compost (not a heavy fertilizer — too much nitrogen produces floppy stems and fewer flowers)
2.If you direct-sowed in April and thinned to 12–18 inches apart, give it time; first-year Eryngium often just sits and builds roots before it does much above ground
3.Don't fertilize after July — you want it hardening off, not pushing tender growth into fall

Stems flopping over or failing to hold upright by midsummer

Likely Causes

Overly rich or moist soil encouraging lush, weak stem growth
Planting in partial shade rather than true full sun (6+ hours), which causes etiolation

What to Do

1.Relocate to your sunniest, driest bed — full sun and lean soil together produce the stiff, self-supporting stems this plant is bred for
2.Skip the compost amendment entirely next season and see if the plant firms up on its own
3.Stake with bamboo canes this year if the flowers are worth saving for cutting, but fix the site conditions before next season

Frequently Asked Questions

How long do Blue Glitter flowers last in a vase?▼

Blue Glitter flowers typically last 2-3 weeks in fresh water when stems are cut properly and placed in cool conditions. Change water every 2-3 days, recut stems at an angle, and remove any lower foliage to maximize vase life. Keeping them away from direct sunlight and ripening fruit helps preserve the distinctive metallic shine.

Is Blue Glitter eryngium good for beginning gardeners?▼

Yes, Blue Glitter is excellent for beginners. It's rated 'Easy' to grow and is a hardy perennial in Zones 3-8. Once established, it tolerates hot, sunny locations with minimal care. The main thing to know is that blooms appear in the second year, so patience is required for first-year plants.

Can you grow Blue Glitter in containers?▼

Yes, Blue Glitter can be grown in containers, though it prefers well-drained soil due to its hardy perennial nature. Use a large pot (at least 12 inches deep) with quality potting mix. Container plants may need occasional watering and feeding during the growing season, especially in hot climates. Ensure the pot has drainage holes.

When should I plant Blue Glitter seeds or seedlings?▼

Plant Blue Glitter in spring after the last frost date, or in fall in warmer zones. Seeds can be started indoors 6-8 weeks before the last frost for transplanting outdoors, or direct sown outdoors. Since this is a perennial, it needs time to establish before flowering, which typically occurs in year two.

What makes Blue Glitter flowers unique?▼

Blue Glitter is prized for its striking metallic sheen on the flowers, giving them a sparkling, jewel-like appearance. As a FleuroSelect Gold Award Winner, it's recognized for exceptional ornamental quality. The blooms attract beneficial pollinators including bees, flies, and wasps, making it valuable for ecological gardens.

Do Blue Glitter flowers attract pollinators?▼

Yes, Blue Glitter flowers are highly attractive to bees, beneficial flies, and wasps. This makes them excellent for pollinator gardens and supporting local ecosystems. The abundant blooms from mid-summer onward provide sustained nectar and pollen sources throughout the season.