Hailing from Argentina, this statuesque Agave look-alike wields a lustrous apple-green rosette with thick, sharp-toothed sword-like leaves. The impressive boldly-textured foundation shoulders steadfast upright flower stalks featuring a bee and butterfly-friendly candelabra of dense greenish white thimbles, which age to a warm cocoa color and make striking additions to cut arrangements. An easy-care semievergreen toughie for mixed borders, massed plantings or sentinel positions, Eryngium agavifolium can lodge amongst other sun-lovers such as Festuca mairei and Verbascum ‘Gainsborough’ where it relishes good drainage and handles drought once established.

Blooms July–September

Size: 4' 0" high x 2' 0" wide.

Hardy to zone 6.

Evoking images of ornate Elizabethan ruffs and flaunting an unsurpassed beauty, this stalwart subalpine European native has been continually cultivated since the 1500s. Wildly popular among bees, butterflies and florists, the dense cone-shaped gunmetal-blue flower heads reside on feathery, soft-to-the-touch collars, each composed of 12 to 18 finely divided, upward curving silver-blue bracts. Stout cerulean-hued stalks with upper, 3-lobed bluish-green leaves elevate the sensational display, while an attractive, green basal rosette of toothed, heart-shaped foliage is sustained by a large taproot that detests being disturbed.

Blooms July–September

Size: 18" – 2-1/2' high x 18" – 2-1/2' wide.

Hardy to zone 5.

This cold-hardy species yields up-curving bracts that are long spiny slivers of silver plus thistle-like metallic-blue blossoms, surmounting branched stems that are tinted blue on their upper extremities. Marked with a smattering of mercury-hued speckles and white veining, deeply cut, gray-green leaves make a low-lying rosette for the unique floral phenomenon.

Blooms July–September

Size: 2' 0" high x 18" wide.

Hardy to zone 4.

This hardy Eryngium is all about blue—the electrifying, iridescent kind that promises to tantalize any garden visitor. A Blooms of Bressingham introduction, ‘Big Blue’s spine-edged green foliage and thick stems create an intriguing candelabra-shaped base for the bright 4 in. wide inflorescences. A blue drama is yours for the viewing as frosty-white bracts and green cones, over the course of several weeks, gradually transmute stunning cerulean shades, imbuing even the stalks below. (PPAF)

Blooms July–September

Size: 2' 0" – 2-1/2' high x 15" – 18" wide.

Zone 4/5.

Blooms July–September

Size: 20" – 2' 0" high x 22" – 2-1/2' wide.

Hardy to zone 4.

Hailing from the Pyrenees, this easily grown perennial boasts a compact clump of crisp undulating gray-green foliage and decorative thistle-like blooms. The distinctive ground-level leaves are artfully chiseled into narrow segments and etched with striking broad white veins. Mustering durable cool-colored intrigue, the round, medium-sized blue-green flowers are tended by long, linear iron-gray bracts.

Blooms July–August

Size: 12" high x 12" wide.

Hardy to zone 5.

Back in Victorian times, Miss Willmott was so enamored with this Eryngium that she secretly scattered its seed in other people’s gardens. And once you’ve seen the blooms, you’ll wish she’d visited yours! Like an ornate Elizabethan ruff, the bracts—ghostly white, rigid and long toothed—subtend exquisite, 4 in. silvery-green floral cones. Supported by sturdy, widely-branched stiff stems, the extraordinary blossoms fade to buff, remaining decorative until frost above glossy basal leaves that are deeply heart-shaped and spineless. Absolutely show-stopping in the border or a container, alluring to bees and unparalleled as a dried flower, the magnificent Giant Sea Holly may not be long-lived, but endures by self-seeding.

Blooms July–September

Size: 3' 0" – 4' 0" high x 2' 0" – 2-1/2' wide.

Hardy to zone 4.

With silvered, narrow spiky ruffs that cradle metallic blue round flower heads, ‘Blaukappe’ makes a sterling addition to dried or fresh bouquets. The vividly colored “blue caps” crest stiff-branched, sturdy bluish stems arising from a handsome green basal rosette of coarsely toothed, rounded and leathery foliage. Let its fantastic mercury-hued accents temper the bronzed blades of Stipa arundinacea.

Blooms June–September.

Size: 2' 0" – 2-1/4' high x 18" wide.

Hardy to zone 4.

Pressing upward through fine saw-toothed, green succulent-like leaves, an abundance of multibranched pewter-blue stems yields some 85 ½ in. shimmering blue pincushions perched on spiny collars. This Ernst Benary selection promises to inspire gardeners and florists alike with a taller sturdy stature and profuse brilliantly colored blooms that mature quickly and make long lasting cut flowers.

Blooms July–September

Size: 2-1/2' – 3' 0" high x 12" – 18" wide.

Hardy to zone 5.

Though this adorable Sea Holly is brimming with cuteness and blue in a big way, its trim globular mound stays small. A dwarf compact rosette of toothed, thick dark green leaves unleashes stiff silver-blue stems and egg-shaped spiny purplish blue heads that appear in wondrous droves all summer long. True to its name and tenacious to boot, ‘Blue Hobbit’s diminutive bearing can be easily tucked into tight spots such as patio pots, between steps or atop stone walls. 

Blooms June–September

Size: 8" – 12" high x 10" – 12" wide.

Hardy to zone 4.

A snowy white multitude of plump conical flower heads perch atop pointed, widely spaced silver bracts. Leafy multibranching stems, pearly hued and steadfast, bolster the luminous blooms, while arising from an attractive dark green basal rosette defined by serrated leatherlike leaves and red-tinted petioles. Pair ‘Silver Salentino’ with Eryngium ‘Blue Glitter’ for a classic look.

Blooms July – September.

Size: 2-1/2' – 3' 0" high x 15" – 18" wide.

Hardy to zone 4.

Lauded as the classy pearlescent twin to Eryngium ‘Blue Glitter’, this no-fuss, bee-friendly perennial affords a scintillating spectacle of dense egg-shaped white flowers with prominent, spiky pewter-colored bracts. The well-branched gray-green flowering stalks emerge from a neat, low growing globular mound forged by glossy, toothed dark green leaves. Pest-free ‘White Glitter’ handles dry conditions plus makes a long-lasting, luminous addition to containers, natural-type plantings or cottage gardens.

Blooms July–September

Size: 2' 0" – 3' 0" high x 8" – 10" wide.

Hardy to zone 5.

An interesting combination of the prehistoric and the refined, this evergreen Eryngium is known for its large-coned, luminous flowers. Linear leaves emerge from a basal rosette with widely spaced spines along their margins. A dramatic collar of upturned, unequal steely green bracts, some reaching the striking breadth of 5 to 6 in. across, serves up central, sea-green flower heads reminiscent of a Protea. Ideal for dried arrangements, this exotic Mexican perennial demands a warm, sunny site with well drained, fertile soil. Give it a blue pot on the patio or another prominent location to bring its remarkable show in-to full view.

Blooms July–September.

Size: 2-1/2' – 3' 0" high x 2' 0" wide.

Hardy to zone 8.

Distinguished from other Sea Hollies by the intense, steel-blue hue infusing its branched stems, upper leaves, and teasel-shaped flowers, ‘Sapphire Blue’ features huge blossoms nestled in dramatic collarlike bracts. With a stance that’s angular yet erect, this sturdy perennial makes a striking counterpoint to the downy white softness of Salvia argentea. (pp#11,088)

Blooms July – August.

Size: 2-1/4' high x 18" wide.

Hardy to zone 5.

The Moroccan Sea Holly is as valuable for its unusual dark and evergreen marbled foliage as for its steel blue flowers set on spiny, silvery bracts atop thick, erect silver-blue stems. Smaller than other Eryngiums, Eryngium variifolium is well suited for an up-front position in the border, in a rock garden or in a container.

Blooms July–August.

Size: 18" high x 10" wide.

Hardy to zone 5.

Smelling like a carrot, looking a bit like a Yucca and once used by pioneers and Native Americans as an antidote to rattlesnake venom, this American tall-grass prairie dweller brandishes bold, lax bluish green rosettes. Characterized by parallel veins, bristly edges and a glaucous finish, the 3 ft. long sword-shaped leaves launch a sculptural wonder of tight-set thistle-style greenish white spheres and pointed ivory bracts held within branched clusters on smooth stiff stems. A low-maintenance perennial that provides fantastic winter interest, Rattlesnake Master obliges dry rocky soil and looks compelling planted with Sesleria heufleriana or Pennisetum spathiolatum.

Blooms July–September

Size: 3' 0" – 4' 0" high x 18" – 2' 0" wide.

Hardy to zone 3.

Presumably hailing from the famed Slieve Donard nursery, this valiant clump-forming perennial develops lustrous, toothed green rosettes, which shoulder erect branching stems topped with sensational soft-to-the-touch metallic-toned flowers. Prized by bees, butterflies and plant-lovers, the large thimble-style steel-hued heads are perched upon broad feathery ruffs of fine-hewn bluish gray bracts. ‘Donard Variety’ offers engaging winter interest, looks exceptional in fresh or dried arrangements, appreciates well-drained somewhat dry sites and makes a sensational partner for cohorts like Perovskia ‘Lacey Blue’ or Verbascum ‘Gainsborough’.

Blooms July–September

Size: 2' 0" – 3' 0" high x 15" – 18" wide.

Hardy to zone 5.

Stylish gleaming green leaves–thick, toothed and tattooed with prominent ivory-colored veins–uphold a fantastic architecture of staunch angular branched stems and extra large teasel-like flowers bathed in galvanizing bright blue hues. Brandishing long lasting late season blooms that honeybees cherish, ‘Jos Eijking’ is best suited for the front of an uncrowded bed, where its extraordinary bearing beguiles any visitor, even in wintertime.

Blooms July–September.

Size: 2' 0" high x 18" wide.

Hardy to zone 5.