Tales of Kale

The season’s first peas and potatoes are such a taste treat, radishes are fun, and everyone pines for the first tomatoes. But kale, I think, is the vegetable most worthy of praise. Here I am in the greenhouse, watering kale transplants for the garden even as, right behind me, kale in beds planted last August are still yielding mature leaves for salads and cooking.

Kale is one of the few vegetables that tolerates heat in summer, cold in winter, and every temperature in between. You can just keep picking the lower leaves as new ones keep growing up top. Neither broccoli, cauliflower, cabbage, nor other members of kale’s family can keep up production like that. And other greens, like lettuce, arugula, and mustard, send up seed-stalks and lose their flavor when days get long or hot. The kale in my greenhouse is now sending up seedstalks but the leaves taste as good as ever. Even the flower-heads themselves, which are like small, loose heads of broccoli, taste good.

Although one sowing, in early spring, could keep me in leafy greenery almost all year long, I do three sowings. The first, in early spring, is for planting out in a few weeks for eating from late spring on through summer. Sometimes, usually, I’ll sow again in July for even more greenery well into autumn and, depending on winter temperatures, into winter. The shorter plants of this later sowing are more apt to be covered by snow, which insulates the leaves and keeps them fresh all winter. In August I sow again for planting in the greenhouse, which gives us fresh kale until spring.

If I had to grow only one vegetable, kale might be the one. (I have a friend who does grow only one vegetable, and it is kale.) Besides its ease of growth and its longevity, kale packs a powerhouse of nutrients: vitamin C, vitamin K, calcium and all those other good things found in cabbage kin, and vitamin H (I made that last one up, but kale no doubt contains a lot of not-yet-known goodies also).

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Seakale (Cramb maritima) is another “kale” I grow. This one might be good eating; I have yet to taste it even though I had it in the garden for over a decade. Besides being a different plant from kale, it is functionally different in that it has a short season of edibility, in early spring, and it is a true perennial, so potentially never needs replanting. Mine needs replanting this year because, for no apparent reason, it died last year.

Seakale is a salt-tolerant plant native to coastal regions of northern Europe, and it was in those regions that it was first moved into gardens for cultivation as a vegetable. Young shoots need to be blanched (grown in the dark) -- by being covered with an upturned clay flowerpot, for example -- to make them palatable. The blanched shoots are very tender, so you might never see them in markets. They should make a nice garden or farmden vegetable, though.

I have yet to taste seakale because each spring I’ve never got around to blanching it. Blanching can’t continue too long or the roots will be starved for energy, which comes from sunlight.

Seakale pulled its weight in my garden in other ways than putting food on the table. Its livened up one corner of the perennial flower bed with its silvery green leaves from which arose, in early summer, loose sprays of small, silvery white flowers, almost like the ocean spray in seakale’s native haunts. I never ate the plant because I didn’t want to weaken it and possibly tone down its spring and summer show.

I sowed new seed this week.

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Continuing the “kale” theme brings me to another vegetable, a close contender with kale for ease of

growth, longevity, flavor, hardiness, and nutrition. Seakale beet, as it is known in Britain; known as Swiss chard here. I plant chard just as I do kale, except less of it because it is less nutritious than kale (high oxalate concentration limits its availability of calcium), slightly less cold-hardy, and I happen not to like its flavor as much.

Seakale beet, or chard, is closely related to beet. In fact, both are the same genus and species. Chard is a beet with extra large leaves and an extra small storage root. But beets are another, story, an underground one.

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SEAKALE, CHUFA, OCA

I’m often questioned, “So what are you growing that’s particularly interesting this year.” It’s a tough question to answer because following the growth of even common plants is interesting year after year, watching how they respond to the vagaries of each year’s weather and pests, changing growing techniques, and other influences. Still, a few plants always elicit a, “You’re growing what?”

Such as, for instance, three edibles: seakale, chufa, and oca. Let’s start with the seakale (Crambe maritima). This plant had been growing at the edge of one of my flower beds for many years but died last year. I never did try eating the plant but had earned a permanent place in the flower bed for its gray-green leaves and attractive sprays of 4-petalled white flowers. Those two characteristics would also rightly land the plant in the cabbage family.

Like cabbage, seakale is edible; unlike cabbage, it needs special treatment before being rendered so. That special treatment is blanching, or shielding the emerging leaves from light to make them more tender and mild-tasting. My plant always seemed too weak to endure such treatment so the plant has been enjoyed only for its good looks. This year, though, I have raised a few seedlings, two of which I planted in the rich soil of the vegetable garden and should be strong enough for a couple of weeks of blanching early next season.

Seakale shoots are too tender for transport so you’ll probably never see them for sale. They were popular in gardens of 200 years ago, though -- Thomas Jefferson’s, for one. If flavor turns out to be the reason the plant fell out of favor, I’ll just continue to grow it amongst the flowers.

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Chufa (Cyperus esculentus) is another edible making a return engagement to my garden. This one makes knowledgeable gardener’s raise their eyebrows because it’s very closely related to a pernicious weed, yellow nutsedge. They’re both the same genus and species. I received tubers from J. L. Hudson, Seedsman (http://www.jlhudsonseeds.net/) who claims that the particular selection that they offer does not become weedy; I confirm that claim.

Chufa’s edible portion are the below ground, almond-sized tubers that have a texture an flavor reminiscent of coconut. So you can grow your own “coconut” even where winter temperatures plunge below zero degrees Fahrenheit. Above ground, chufa (and yellow nutsedge) have a grassy appearance except that rolling one of the clumping leaves between your thumb and index finger reveals the triangular cross-section characteristic of sedges. Grass blades are flat.

The main problem in growing chufa is separating the harvested tubers from the soil. Gravel or small stones are about the same size, and a lot harder on your teeth should you accidentally bite into one in a batch of chufa. My plan is to hose down each harvested clump well and then to stir the tubers in water just enough to let anything with the density of stone settle out first. And chew carefully.

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Oca (Oxalis tuberosa) is perhaps the most interesting new plant in my garden, among edibles, at least. It’s related to one of my worst garden weeds, creeping wood-sorrel (O. corniculata). It’s a staple food of the Andean highlands and an iffy crop, around here at least.

The limitations to growing oca are that it needs a long season and it forms tubers only when days grow short (at which time cold weather is likely to kill stems and leaves). On the other hand, the plant has been cultivated for centuries so there are many varieties. New Zealanders have been enjoying and growing oca (which there are called yams) for about 150 years and their varieties are more likely suited here.

I don’t know the provenance of the oca tuber I planted so it could just take up garden space the whole season then die back leaving nothing of value underground. My plan is to keep it warm in autumn beneath a cover of clear plastic, which would be needed even for the most adapted varieties.

And then there’s the flavor. Many varieties, many flavors, from tart to sweet. Oca is used like potatoes and also eaten raw. In the Andes, super-tart varieties are freeze-dried by being left outside on the ground on hot, sunny days and cold, freezing nights. Stamping on defrosting tubers speeds water removal. Interesting, yes?

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Seakale, chufa, and oca are among perennial vegetables that, once planted, come back year after year of their own accord. Others include black salsify, groundnut, Jerusalem artichoke, ramps, skirret, Welsh onion, and, of course, asparagus. For more about perennial vegetables, see Perennial Vegetables: From Artichokes to Zuiki Taro, A Gardener's Guide to Over 100 Delicious and Easy to Grow Edibles by Eric Toensmeier. 

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