Sea Holly is a useful perennial for its ability to cope with hot, dry conditions and coastal locations. Eryngium 'Blue Steel? produces dramatic cones of tiny blue flowers that are surrounded by a spiky, electric-blue collar. The tall flower stems bring fabulous texture to sunny borders, and are prized by flower arrangers for adding to summer bouquets, either fresh or as a dried flower. Loved by pollinating insects, Eryngium makes a useful addition to a wildlife garden, or for filling gaps in cottage garden borders. Height: 90cm (36). Spread: 45cm (18).