Eryngium planum 'Seven Seas' is a herbaceous 

 in the Apiaceae with thistle-like flowerheads composed of small blue cones surrounded by spiky bracts. Stems are branched and silvery-blue, carrying the flowerheads above a basal rosette. Flowering runs from June to September. The cultivar presents a compact habit, typically suited to mid-border or gravel planting.

Eryngium planum 'Seven Seas' belongs to the Apiaceae and follows the species’ characteristic of producing conical, blue flowerheads encircled by stiff, spiny bracts. The species originates from countries across central and south‑eastern Europe and into Central Asia, where it grows as a short-lived herbaceous perennial. In the garden it appears as a multi‑stemmed plant with silvery‑blue, branched stems bearing the distinctive inflorescences. Plant where the architectural flowerheads can be seen; place individual plants so the spiky bracts and cones are not hidden by taller neighbours. Keep soil free‑draining and avoid waterlogged hollows to preserve stem integrity and flowering potential. Cut back stems after flowering to tidy the clump and allow fresh basal growth the following season. Labels and nursery descriptions will indicate whether a specific cultivar tolerates the conditions in your plot. Use 'Seven Seas' where the blue flower colour and sculptural bracts will be visible from paths or patios: gravel beds, the front to middle of mixed borders and sunny, open positions suit its sculptural habit. The blue conical flowerheads and spiky bracts give clear summer punctuation from June to September.

Eryngium planum 'Seven Seas' is a herbaceous perennial in the Apiaceae with thistle-like flowerheads composed of small blue cones surrounded by spiky bracts. Stems are branched and silvery-blue, carrying the flowerheads above a basal rosette. Flowering runs from June to September. The cultivar presents a compact habit, typically suited to mid-border or gravel planting.

Eryngium planum 'Seven Seas' bears blue conical flowerheads with spiky bracts and flowers from June to September.

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