Eryngium also known as Eryngo, Sea holly, Alpine sea holly, Amethyst sea holly, Miss Willmott’s ghost, Flat sea holly, Moroccan sea holly, Rattlesnake-master are hairless annuals, biennials and deciduous or evergreen perennials. Those that are native to dry, rocky places and coastal areas in Europe, N. Africa, Turkey, C. Asia, China and Korea usually have taproots and congested heads of blue or white flowers. Those that are from often wet and marshy grassland in Mexico, Brazil, Argentina, and warm temperate regions of North, Central and South America, usually have fibrous roots and evergreen foliage with greenish white, occasionally purplish brown flowers. Their unique, egg-shaped, steel blue, long lasting flowers provide a tremendous garden presence.
USES: Cut flowers, Dried flower arrangements, Bee and butterfly gardens, Borders, Low maintenance gardens, Informal beds and borders, Wildflower gardens, Mass plantings, Coastal gardens, Rock gardens, Cottage gardens
TOLERATES: Drought, Poor soils, Deers, Rabbits, Heat, Winds, Salt Sprays, Sandy soils
Botanical Name: Eryngium planum Blue
Common Name: Flat sea holly, Flachblatt-Mannstreu
Type: Clump-forming, taproot, evergreen Perennial
Flower Color: 1 in. (2.5cm) long blue flowers
Foliage Color: Dark green 2-4 in. (5-10cm) long with blue tinted, strong, branching stems
Flowering Time: Midsummer to early autumn
Plant Height: 36 in. (90cm)
Plant Width: 18 in. (45cm)
Light Requirements: Full Sun
Water Requirements: Dry
Soil Requirements: Poor to moderately fertile, well drained soil
USDA Zone: 5-9
AHS Heat Zone: 9-5
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