Alphabetical Plant Listing

Eryngium x oliverianum (Oliver Sea Holly)

Oliver Sea Holly, Oliver Eryngo


Eryngium x oliverianum (Oliver Sea Holly) is an upright perennial with basal rosettes of heart-shaped, strongly toothed, dark green leaves. From mid-summer to early fall, sturdy leafy violet-blue stems bear large, cone-shaped, thistle-like, blue to lavender-blue flower heads. Each flower head is surrounded by narrow, spiny, metallic-blue bracts. Attractive to bees and butterflies but deer resistant, this striking Sea Holly survives in a wider range of soil types than many more difficult eryngiums. Eryngium x oliverianum is a cross between E. planum and E. giganteum. According to many, it has the strongest blue stems and flowers of any eryngiums.

  • Recipient of the prestigious Award of Garden Merit of the Royal Horticultural Society.
  • Grows in clumps of stiffly erect, branched stems up to 24-36 in. tall (60-90 cm) and 18-24 in. wide (45-60 cm)
  • Performs best in full sun in fairly dry, poor to moderately fertile well-drained soils. Tolerates light shade, poor soils, drought and salt.
  • Excellent choice for gravel gardens, cottage gardens and coastal gardens. May be planted as a single specimen or in groupings. Perfect for cut or dried flower arrangements too!
  • Although you can cut back flower stems after flowering the seedheads are a very attractive feature so are usually left over winter
  • Watch for leaf and bud eelworms, powdery mildew and root rot.
  • Propagate by root cuttings in late winter

Learn How To Plant, Care, and Grow Spectacular Sea Holly (Eryngium)

Attractive, Sea Holly plants (Eryngium) are striking ornamental perennials grown for their arresting, thistle-like, silvery or blue tinted flower heads adorned with a ruff of showy bracts. Blooming in summer and sometimes into fall, they are exceptionally care-free plants if they are given a well-chosen site. Here are some basic rules that need to be followed to enjoy their splendid flowers.Read More

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Requirements

Hardiness 5 – 8
Heat Zones 5 – 8
Plant Type Perennials
Plant Family Eryngium - Sea Hollies
Exposure Full Sun
Season of Interest Summer (Mid,Late)
Fall
Height 2' – 3' (60cm – 90cm)
Spread 1' – 2' (30cm – 60cm)
Spacing 24" (60cm)
Water Needs Low
Maintenance Low
Soil Type Chalk, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Well-Drained
Characteristics Dried Arrangements, Cut Flowers, Plant of Merit, Showy
Tolerance Deer, Drought, Dry Soil, Salt
Attracts Birds, Butterflies
Garden Uses Beds and Borders
Garden Styles Coastal Garden, Gravel and Rock Garden, Informal and Cottage, Prairie and Meadow

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Great Plant Combination Ideas with Eryngium - Sea Hollies

Guides with Eryngium - Sea Hollies


By Del Boy /Shutterstock

While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.


Requirements

Hardiness 5 – 8
Heat Zones 5 – 8
Plant Type Perennials
Plant Family Eryngium - Sea Hollies
Exposure Full Sun
Season of Interest Summer (Mid,Late)
Fall
Height 2' – 3' (60cm – 90cm)
Spread 1' – 2' (30cm – 60cm)
Spacing 24" (60cm)
Water Needs Low
Maintenance Low
Soil Type Chalk, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Well-Drained
Characteristics Dried Arrangements, Cut Flowers, Plant of Merit, Showy
Tolerance Deer, Drought, Dry Soil, Salt
Attracts Birds, Butterflies
Garden Uses Beds and Borders
Garden Styles Coastal Garden, Gravel and Rock Garden, Informal and Cottage, Prairie and Meadow

Great Plant Combination Ideas with Eryngium - Sea Hollies

Guides with Eryngium - Sea Hollies

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