Eryngium giganteum, Miss Willmott’s Ghost

Plant of the Month July 2025

This is a low-maintenance biennial from the Middle East. Legend has it that Miss Willmott, (Ellen Willmott, 1858-1934) loved the plant and surepticiuosly dropped seeds in appropriate places when she visited gardens. Another Giant Sea Holly, Eryngium pandanifolium, is native to South America.

GENERAL INFORMATION:

Common Name: Miss Wilmots Ghost, Giant Sea Holly, Giant Ornamental Thistle Flower, Tall Eryngo.

 

Eryngium giganteum, inflorescence.

Cultivars: ‘Silver Ghost’.

Life Cycle: Herbaceous biennial. Most Eryngium sp. are perennial.

Height: 60-100cm, about 100cm wide.

Bloom Time: June to August. 

Flower Colour & Size: Tight cone-shaped umbel of small greenish blue flowers with blue anthers, surrounded by silvery, spiky, palmately divided, 7cm bracts.

  

 Eryngium giganteum, with pollinator (Digger wasp, Sphex ichneumoneus).

Leaves: A basal evergreen rosette of 15cm long, heart shaped green leaves, forms during the first year. The leaves wither as the flower stalk appears

 

Eryngium giganteum leaf.

 Range: Native to Turkey, Caucuses, Iran.

Habitat: Tall grass prairies and dry, well-drained soils. 

CULTIVATION: 

Plant: in a suitable place when small. The tap-rooted plant resents disturbance.

Light: Full sun.

Soil: Most soils - prefers moist, well drained fertile soil.

Water: Medium. Drought tolerant.

USDA Hardiness: Zones 4-7.

Companion planting: Other sun loving perennials.

Problems: Nothing serious.

 

Eryngium giganteum, maturing seed (fruit) heads.

Propagation: Will self-seed. Sow @ 20°C for 6 weeks, then 4°C for 6 weeks, slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle.

 

Eryngium giganteum, seed dispersal.

Pollinators: Bees, butterflies, hover flies.

References:

https://www.missouribotanicalgarden.org/PlantFinder

https://onrockgarden.com/index.php/germination-guide

 

Text and images supplied by Anna Leggatt (Toronto Master Gardener)