Sea kale is a very hardy perennial vegetable that grows clusters of pale blue/green leaves, about 15 by 30 cm, that get purple near the base and around the margin. The leaves are thicker and more succulent than curly kale, making it excellent for soups and stews. It is an ancient brassica, and in late summer it will produce broccoli-like florets that can reach almost a meter tall.
Sea kale is used to growing in sandy, salty soils, but it will grow just as well in almost any soil you put it in, so long as there is decent drainage. In the Southside Permaculture Park, we even have it growing in clay mixed with some leaf mulch and compost, and it seems very happy. Full sun is preferred for maximum productivity, however it will still grow in moderate to heavy shade (albeit much less) and will be sweeter and softer if grown in heavy shade. Sea kale tends to stay where it was planted, not spreading but still holding its ground, making it a good border plant to prevent grass encroachment. Sea kale can be propagated from seed by cracking open the hard shell around the true seed and placing in loose, moist soil , or cloned via root cuttings. When taking root cuttings, be sure to use a sharp, clean knife and make sure each section is at least two inches long. Place the cuttings vertically in the ground with the top facing up, buried just below the soil surface . Cuttings are best planted in late March to early April after the soil thaws, but they will take just about any time of year that the soil is not frozen.
Sea kale makes an abundance of tasty, succulent leaves that serve a great addition to salads, soups, and stews. The florets are another great vegetable, used raw, steamed, or sautéed, very similar to broccoli. Sea kale is very cold hardy and incredibly resistant to deer and rabbit forage. It holds its ground well, making it a useful border plant for perennial vegetable beds to help keep grass in the pathways from encroaching on the bed.