Eryngium giganteum

Inflorescence
Common Name: Miss Willmott's ghost 
Type: Herbaceous perennial
Family: Apiaceae
Native Range: Caucasus, Turkey
Zone: 4 to 7
Height: 2.00 to 4.00 feet
Spread: 1.00 to 3.00 feet
Bloom Time: June to August
Bloom Description: Bluish-silver
Sun: Full sun
Water: Medium
Maintenance: Low
Flower: Showy
Leaf: Colorful
Other: Thorns
Tolerate: Drought, Dry Soil

Culture

Easily grown in medium moisture, well-drained soils in full sun. Prefers moist, fertile soils. Tall plants tend to sprawl, particularly if grown in overly fertile soils or in anything less than full sun. This is a taprooted plant that transplants poorly and is best left undisturbed. Plants are biennial. In the first year, basal rosettes of foliage form that overwinter as evergreen rosettes. In the second year, plants send up flowering stems, produce flowers and finally produce seed before dying. As is the case with foxgloves (Digitalis) and hollyhocks (Alcea), these eryngiums will self-seed and remain in the garden from year to year as if they were perennial unless spent flower heads are deadheaded prior to seed drop. Easily grown from seed.

Noteworthy Characteristics

Eryngium giganteum, commonly called sea holly or giant sea holly, is a large, coarse, thistle-like, clump-forming biennial or short-lived perennial that typically grows 2-4’ (less frequently to 6’) tall. Features basal rosettes of heart-shaped green leaves (to 6” long) and smaller spiny ovate stem leaves. Tiny, stemless, bluish-silver flowers tightly packed into cone-shaped, thistle-like heads (umbels to 4” long) appear in late spring in branched clusters atop stiff stems rising from the centers of the basal rosettes. Each flower head is subtended by a showy collar of spiny-tipped, holly-like, silver-gray bracts (each bract to 2.5” long). This species is sometimes commonly called Miss Willmott’s Ghost in reference to Ellen Willmott (1858-1934), English gardener in Essex, who so loved this plant with its silvery ghost-like appearance that she reportedly scattered its seed on a regular basis in gardens she visited without telling the owners.

Genus name comes from an ancient Greek name used by Theophrastus for a plant which grew in Greece (probably Eryngium campestre) or is a Greek reference to the prickly or spiny nature of plants in this genus.

Specific epithet means unusually tall or large.

Problems

No serious insect or disease problems. Taller plants may need support.

Uses

Borders. Also may be grown in containers where they will grow more compactly.