Eryngium zabelii 'Big Blue' (Sea holly 'Big Blue')
'Big Blue' is an upright, clump-forming, deciduous perennial with spiky, deeply divided, silvery grey-green, leaves and, in summer, stiff, branched stems bearing cone-shaped, blue flowerheads surrounded by prominent, spiny, silvery-blue bracts.
Plant in poor to moderately fertile, well-drained soil in full sun. Drought tolerant once established. Does not tolerate shade or winter wet. Will reach a height of 0.8m and a spread of 0.45m after 2-5 years.