This spiky herbaceous perennial is related to the sea holly which still grows wild on a few sandy shores in Britain. It is a striking plant for the summer border, bothand stalks being a metallic steely blue. The are blue-green, spiny and deeply cut. It grows 2 to 3 feet (60 to 90 cm) tall, and the branching stalks bear glinting conical flowers circled with bristly bracts, like those of wild teasel. Miss Jekyll, skilful with words as well as plants, described it as having ‘an admirable structure of a dry and nervous quality’.
It needs a dry, sunny place with very good– sandy or chalky soils suit it well – and the go very deep, making it impervious to drought. The artist John Piper, ‘a great man for thistles’, grows it in the parallel borders of his farmhouse garden in the Chilterns, with echinops, giant sunflowers, rud-beckias, golden rod, and other traditional cottage flowers. It is excellent for and drying for winter bouquets.
Three plants, 18 inches (45 cm) apart, would make an exciting group in any flower border, though Miss Jekyll, usually working on a grand scale, used eryngiums in bold masses.
Some gardeners prefer the taller E. giganteum, with paler, silvery flowers, known as ‘Miss Willmott’s Ghost’, but this is, and must be re-sown.