Eryngium leavenworthii Purple Sheen | Leavenworth’s Eryngo Seeds

Eryngium leavenworthii ‘Purple Sheen’ is a striking ornamental and cut-flower variety with intensely violet-purple, spiky flower heads, blue-purple bracts and decorative foliage on strong upright stems. Native to the dry prairies of the central United States, it thrives in sunny, well-drained conditions and brings an unusual architectural texture to fresh bouquets, dried arrangements and garden plantings.

Unlike many perennial Eryngium species, Eryngium leavenworthii is generally grown as an annual and can flower in its first year from seed. Purple Sheen has a relatively long growing season, so early sowing is recommended when growing it for cut flowers.

Plant Information

• Botanical Name: Eryngium leavenworthii
• Variety: Purple Sheen
• Common Name: Leavenworth’s Eryngo
• Also known as: Leavenworth’s Eryngium
• Family: Apiaceae
• Life Cycle: Annual
• Flower Colour: Violet to blue-purple
• Plant Height: Approx. 80–120 cm
• Plant Habit: Upright, strongly branched
• Use: Cut flower, dried flower, ornamental garden plant
• Position: Full sun
• Soil: Light, well-drained soil
• Days to Germinate: Approx. 12–20 days under suitable conditions
• Germination Temperature: 18–20°C
• Seed Count: Approx. 10,000–15,000 seeds/g
• Time from Sowing to Flowering: Approx. 6–7 months

Purple Flowers & Architectural Texture

Purple Sheen develops unusual violet-purple flower heads surrounded by pointed, spiny bracts, creating a distinctive architectural appearance.

As the plants mature, the stems, flower heads and bracts develop increasingly rich purple and blue-purple colouring. The unusual shape provides excellent contrast to softer flowers such as cosmos, zinnias, dahlias and lisianthus.

The stems are particularly useful as a textural filler for bouquets, while the flowers can also be dried for long-lasting arrangements.

When to Sow

Because Purple Sheen requires a relatively long period from seed to flowering, early indoor sowing is recommended for reliable first-year flowering.

For cut-flower production, start seeds indoors in late winter to early spring.

Allow approximately 6–7 months from sowing to flowering, depending on temperature, light levels and growing conditions.

In climates with mild winters, autumn sowing may also be possible, provided young plants can be protected from excessive winter moisture and severe conditions.

How to Sow Eryngium Purple Sheen

Sow into a fine, moist and well-drained seed-starting substrate.

Place the seeds on the surface and cover lightly with a thin layer of substrate or fine vermiculite.

Maintain approximately 18–20°C and keep the substrate evenly moist but never waterlogged.

Under suitable conditions, Purple Sheen may germinate in approximately 12–20 days.

Eryngium germination can sometimes be irregular. If seeds fail to germinate after a reasonable period, a short period of cold stratification can help break dormancy.

Cold Stratification

Cold treatment is not necessarily required for every seed lot, but it can be useful when germination is slow or irregular.

Keep the moist seed tray or seed container at approximately 4°C for 2–3 weeks, then return it to suitable germination conditions.

Some Eryngium seeds can remain dormant considerably longer, so do not discard a seed tray too quickly if germination is delayed.

Growing the Seedlings

Once seedlings have emerged, provide plenty of light and good air circulation.

Allow the surface of the growing medium to dry slightly between watering while avoiding prolonged drought in very young seedlings.

Eryngium develops a long taproot, so avoid keeping seedlings in small cells for too long.

Deep cells or individual pots are useful because they allow the root system to develop with less disturbance.

Transplanting

Transplant young plants to their final growing position while they are still relatively small.

Eryngium develops a deep root system and does not appreciate repeated root disturbance, so handle the root ball carefully during transplanting.

Plant outside after the young plants have been hardened off and conditions are suitable.

Planting & Growing

Purple Sheen performs best in full sun and light, well-drained soil.

Once established, it is well adapted to relatively dry growing conditions. Avoid heavy, constantly wet soils, which can result in weaker growth and poorer plant quality.

For the strongest plants and most intense colour, provide:

• Full sun
• Excellent drainage
• Moderate fertility
• Good air circulation
• Regular moisture while plants establish
• Drier conditions once well rooted

Avoid excessive fertilisation, particularly high nitrogen levels, which can encourage soft growth.

Days to Bloom

Purple Sheen has a long growing period of approximately 6–7 months from sowing to flowering.

For example, plants sown early in the year can flower during summer, although the exact timing depends on sowing date, temperature, light and growing conditions.

Because of this long development period, early sowing is particularly useful for growers who want dependable first-year flowers.

Harvesting for Cut Flowers

Harvest when the flower heads and surrounding bracts have developed good colour and feel firm.

For fresh arrangements, stems can be harvested as the characteristic purple colour becomes well developed.

Cut strong stems with clean, sharp secateurs and place them immediately into clean water.

The unusual spiky flowers provide excellent structure and texture in mixed bouquets.

Harvesting for Drying

Purple Sheen is also an excellent dried flower.

For drying, cut stems when the flower heads have developed their characteristic colour but before they become overmature.

Remove unnecessary foliage, gather the stems into small bunches and hang them upside down in a dry, dark and well-ventilated place.

The rigid flower heads retain their architectural form particularly well when dried.

Why Grow Purple Sheen?

Intense violet-purple colour • Unusual spiky flower heads • Strong 80–120 cm stems • Flowers in the first year • Excellent bouquet texture • Fresh and dried flower use • Thrives in sunny, well-drained conditions • Distinctive architectural garden plant

Eryngium leavenworthii ‘Purple Sheen’ is an excellent choice for flower growers looking for an unusual purple textural flower for cutting and drying, while its dramatic colour and sculptural form also make it an eye-catching addition to sunny garden plantings.