The silver-blue petals and thistlelike foliage of sea holly (shown here with bright green dill) stand almost hip-high in the flowerbed. This ghostly giant is a biennial, and the plant readily reseeds itself. Grows comfortably in Zones 5-8.
'Big Blue' Sea Holly for sunny garden, deer-, rabbit-, and drought-resistant perennial shows off silvery foliage and iridescent silvery-blue flowers in midsummer...wonderful cut flower and prime choice for butterfly gardens. Name: Eryngium 'Big Blue' Full sun well-drained soil Size: To 30 inches tall and wide Zones: 4-9
Eryngium plants, also known as sea holly flowers, make striking additions to the garden. Mostly native to Europe and the Mediterranean, these plants generally grow anywhere from 18 to 36 inches tall with a one-foot spread. Their green or silvery-blue stems give way to green or blue cones surrounded by spiky silver, white, green, blue or violet bracts, which bloom from summer throughout fall.
Eryngium × zabelii 'Jos Eijking' (PBR) - This delightful sea holly has long lasting, flowers that arrive in mid- to late summer, turning bright metallic-blue as they age and usually lasting well into the autumn. They have a strong architectural shape, so are best in uncrowded borders where they can really stand out on their own. Honey bees love their flowers so they are a perfect for adding to a sunny, wildlife-friendly garden.