Overview
Eryngium amethystinum is a clump-forming, upright and branching; some form basal rosettes perennial in the genus Eryngium, part of the Apiaceae family, with deciduous or evergreen; leathery, often spiny, sometimes marbled or silver-veined foliage. Eryngium amethystinum grows best in full sun, and tolerates most soils and neutral to alkaline pH. Its UK hardiness is rated H4-H7. Suggested uses include gravel gardens, rockeries, borders and drought-tolerant gardens. It is native to Italy and Sicilly & Balkans.
About
Eryngium amethystinum is a clump-forming perennial in the Apiaceae, notable for its silvery-blue bracts and spiny, leathery leaves. It forms upright, branching stems and can produce a basal rosette of foliage. Flowers appear from June to September, held above the leaves on exposed plants. It favours sharply drained, neutral to alkaline soils and sun on a south- or west-facing site.
Wikipedia contributors, CC BY-SA 4.0 — Eryngium amethystinum
About the genus
Eryngium is a genus of flowering plants in the family Apiaceae. There are about 250 species. The genus has a cosmopolitan distribution, with centres of diversity in the western Mediterranean, South America and Mexico.
Wikipedia contributors, "Eryngium", CC BY-SA 4.0 — Eryngium
In the garden
Eryngium amethystinum originates from parts of the eastern Mediterranean (Italy, Sicily and the Balkans) and suits dry, sunny sites. As a clump-forming perennial in the carrot family (Apiaceae) it bears leathery, often spiny leaves with occasional silver veining, and branching stems that lift the flowerheads clear of the foliage. It flowers June to September. Plant it where drainage is excellent: poor to moderately fertile sand, chalk or gravel suits it best and winter wet will prove fatal. Give a full-sun, south- or west-facing aspect on an exposed site so the tap-root and crowns stay dry in winter. The hardiness range H4–H7 indicates it is average to fully hardy across most UK gardens, provided soil is sharply drained. Use Eryngium amethystinum in gravel gardens, rockeries or drought-tolerant borders where architectural form is wanted. It pairs well with low grasses and other calcicole perennials on alkaline soils. Expect a long summer display: silvery-blue bracts and blue–purple flowerheads rise above the spiny basal leaves from June through September.
Growing conditions
Best soil and position for Eryngium
- Sunlight
- Full sun
- Soil type
- Poor to moderately fertile, sharply drained sand, chalk or gravel
- Soil pH
- Neutral to alkaline
- Soil moisture
- Well drained to dry; winter wet is fatal
- Aspect
- South or west facing
- Exposure
- Exposed
- UK hardiness
- H4-H7
Plant details
Eryngium amethystinum size, habit and characteristics
- Plant type
- Perennial
- Habit
- Clump-forming, upright and branching; some form basal rosettes
- Foliage
- Deciduous or evergreen; leathery, often spiny, sometimes marbled or silver-veined
- Suggested uses
- Gravel gardens, rockeries, borders, drought-tolerant gardens
- Native to
- Italy, Sicilly & Balkans
Care notes
Pruning and caring for Eryngium amethystinum
- Cultivation
- Give them the hottest, poorest, best-drained position in the garden. Rich soil produces soft growth that flops and rots, so resist feeding. Most resent disturbance because of a long taproot, which is also what makes them genuinely drought-tolerant once settled - plant young and leave alone. Excellent in gravel gardens and on thin chalk.
- Pruning
- Cut spent stems back in early spring rather than autumn, since the dried heads are among the best winter silhouettes in the border.
- Propagation
- Sow seed fresh in autumn, as germination becomes erratic once stored. Root cuttings taken in winter are the reliable route for cultivars; division rarely succeeds given the taproot.
- Pest resistance
- Slugs damage young growth, particularly on the rosette-forming species; otherwise little troubled.
- Disease resistance
- Healthy where drainage is adequate. Root and crown rot follow winter waterlogging, which is by far the commonest cause of loss.
Frequently asked questions
How do I grow Eryngium amethystinum?
Give them the hottest, poorest, best-drained position in the garden. Rich soil produces soft growth that flops and rots, so resist feeding. Most resent disturbance because of a long taproot, which is also what makes them genuinely drought-tolerant once settled - plant young and leave alone. Excellent in gravel gardens and on thin chalk.
Where is the best place to plant Eryngium amethystinum?
Eryngium amethystinum prefers full sun. It suits exposed positions.
What soil does Eryngium amethystinum need?
Eryngium amethystinum is adaptable and grows happily in most soil types, including poor to moderately fertile, sharply drained sand and chalk or gravel. It prefers neutral to alkaline soil. Aim for soil that stays well drained to dry; winter wet is fatal.
How do I prune Eryngium amethystinum?
Cut spent stems back in early spring rather than autumn, since the dried heads are among the best winter silhouettes in the border.
Is Eryngium amethystinum hardy in the UK?
Eryngium amethystinum has an RHS hardiness rating of H4, meaning it is hardy through an average UK winter, tolerating -10 to -5°C.
How do I propagate Eryngium amethystinum?
Sow seed fresh in autumn, as germination becomes erratic once stored. Root cuttings taken in winter are the reliable route for cultivars; division rarely succeeds given the taproot.
More in the Eryngium genus
- Eryngium agavifoliumSea Holly
- Eryngium bromeliifoliumpineapple-leaved eryngo
- Eryngium eburneum
- Eryngium horridumSea Holly
- Eryngium planum 'Blaue Kappe'Blue Eryngo
- Eryngium planum 'Seven Seas'Blue Eryngo
- Eryngium proteiflorumprotea-like-flowered eryngo
- Eryngium serraSea Holly
