Sea holly (Eryngium 'Big Blue') dazzles the eye with iridescent blue flowers with blue stems and leaves in an inflorescence resembling a candelabra. Flowers continue to be produced over a long flowering period. Four inch-diameter bracts surround the central cone of fertile flowers on a plant that matures about 30 inches tall by 18 inches wide.

It is a butterfly attractant, and its seeds are a favorite of songbirds, but deer avoid it, as they do not like the prickly spines on the leaves. A member of the carrot family—famous for candelabra-like umbels of flowers—this striking plant needs well-drained soil and full sun to reach maximum coloration. The flowers of this genus have long been treasured by dry flower arrangers. In medieval Europe, the candied roots were used in tonics.