One of the finest perennial vegetables for temperate climates. Since ancient times, seakale has been a traditionally harvested wild vegetable of northern and western European coastlines. Evidence of its use stretches at least back to Mesolithic coastal southern Sweden (around 6500 BC). “Crambe” is in fact an ancient Greek word for a type of cabbage though it supersedes the advent of the cabbage by thousands of years. Though seakale differs from the usual cabbage or kale by its perennial habit and form, instead growing in clumps of rosettes of thick succulent leaves close to the ground. It does however share a close genetic affinity to both cabbage (Brassica oleracea) and Radish (Raphanus sativus).
Once a popular Victorian kitchen garden delicacy and grown on a huge scale for market, seakale eventually fell into obscurity. In recent years, seakale has made a resurgence especially among agroecologists, permaculture gardeners, and those looking to grow perennial vegetables and perennial greens. Traditionally, terra cotta forcing pots were used in spring to exclude light and force very tender sweet pale growth (similar to rhubarb or asparagus culture). Grown this way, shoots are harvested when about 6 inches tall. These days, buckets can be used to the same effect, however this variety will still produce relatively mild shoots compared to most other seakale varieties even without light exclusion. Once the plants have been blanched, it is important to allow them to rest and recover over the rest of the season. Like other perennial vegetables, patience is a virtue and you will get better results if you allow the plant to mature before your first harvest. We recommend waiting to harvest until the third year.
The shoots are not the only edible part! Individual young leaves make a wonderful addition to spring salads or stir-fries. In its second year, small “broccolini” heads can be lightly steamed or eaten raw. Pollinated flowers become round light-green pods (resembling peas) which offer a delicious sweet crunch with a slight radish flavor. The root also has a pleasant flavor and can be roasted or boiled during the winter as well.
This Improved Lilywhite is a new reselection of the old Victorian variety with a much finer flavor compared to wild seakale. The name comes from the “lily white” pale blue-green color of the leaves. These seeds are the result of several cycles of selection from a number of sources of Lilywhite for the most vigorous and drought-resistant plants.
Contrary to the name, seakale does not need to be grown by the sea! However, seakale does flourish in soil that is neutral to slightly alkaline and has consistent moisture. Hardy to Zone 5 with mulching, it grows well in full sun to part shade, but does not like excessive heat or drought and can temporarily die back during those conditions (similar to rhubarb). Can benefit from some shade in really hot dry climates, along with plenty of water and a soil with a good organic material content. Seakale benefits from mulches and plenty of calcium. That said, this halophyte (salt-lover) evolved in a surf-sprayed landscape amongst the rocks above the high tide line and does thrive as the perfect perennial vegetable for people growing near the sea.
Prior to planting, make sure to gently and carefully crack open the corky outer pod to reveal the tender, easily crushed seed inside. Seeds can be freed by chipping away at the corky pod with nail clippers, jewelry pliers, or something similar (Nate has become quite adept at doing this with his teeth!). Planting the seed pod without this process typically results in very low and erratic germination. Seeds should be planted soon after being freed from their pods. Even with this fresh quality seed, germination is naturally low and variable, so make sure to sow this seed as soon as you can. Expect germination over a two-month period with some stragglers.
Once your seakale patch has been established for several years, plants can be propagated vegetatively. Favorite plants can be easily increased by taking cuttings, called “thongs”, during the winter, after the plants have died back down to the ground. A good thong has at least one short stubby growing stem with an intact growth point. The roots are a bit corky and rubbery and easy to divide by hand. Long term, this is the quickest way to propagate plants in your garden.
As worthy as this is for the vegetable garden, Improved Lilywhite Seakale also provides large sprays making it a great permanent addition to the ornamental flower garden as well. The flowers have an intoxicating honey scent and are very attractive to a range of beneficial insects and pollinators.
These seeds are the result of several cycles of selection by our friend Chris Homanics in Washington of Head, Hands, Heart Nursery and Seed, who started with a number of sources of Lilywhite and bred for the most vigorous and drought resistant plants — making this an excellent improvement on the most popular strain of seakale.
NOTE: A small portion of seed pods will contain an immature seed or will even be empty, though in order to provide you with the best quality seeds, the smallest and lightest pods have been graded out.