Perennial of the Brassicaceae family, the sea kale is native to the Atlantic and North Sea coasts, from southern Scandinavia to the French, British, and Iberian shores, as well as on some coasts of the Baltic and Black Seas. It colonizes pebble ridges, coastal cliffs, and coarse sands, in conditions of sea spray, strong winds, and soil almost devoid of organic matter.
It develops a powerful fleshy and deep rootstock, forming large architectural clumps 40 to 60 cm in height, reaching up to 80 cm in bloom. The leaves are very large, wavy to lobed, with a pronounced glaucous blue-gray, leathery and quilted appearance, with crenate margins. Their sculptural aspect is one of the most remarkable features of the species.
The flowers, pure white, are gathered in large airy and highly branched corymbs, with a cloudy and light effect that contrasts with the mass of the foliage. Their light fragrance is noticeable in calm weather.
In its natural habitat, its flowering extends from May to July. In cultivation, it generally occurs in May-June.
The young blanched shoots of sea kale have long been consumed as a spring vegetable, in the manner of asparagus, particularly in Great Britain.
In cultivation, it requires full sun, a deep, well-drained, sandy or gravelly soil, and perfectly tolerates drought and sea spray. It does not tolerate heavy and wet soils in winter. Its hardiness is good.