Perennial kale breeding
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Tag Archives: perennial kale
The Joy of Promiscuity
This might sound like a rather abrupt change of subject for this blog, but no no, I’m still talking about vegetables, and any high jinks herein are purely plant-based. It does, however, begin with a seedy tale of contacts made on the internet…
A bit over a year ago, I offered some turnip-rooted chervil seed to members of a Facebook group I’m on. A few people replied and little packets duly went out. One recipient kindly sent me some kale seeds in exchange, along with a note explaining that they were from an OP grex. A quick Google later, I knew what an OP grex was. Essentially, a grex is a particular cross between two previously-named gene pools (which may be species or may be crosses themselves), plus any further offspring that arise from members of the grex crossing with each other or with the original parent populations. OP simply stands for open-pollinated.
Usually, seed-saving is quite a conservative affair. The aim is to propagate a named variety, keeping it as ‘clean’ as possible by avoiding pollination by any other variety. Seed-saving manuals give the isolation distance required for each species: up to a mile in the case of the brassicas. This keeps the variety stable, of uniform and predictable qualities. This is particularly important when one ancestral species has differentiated into a number of quite different forms: cauliflower and Brussels sprout will cross quite happily, but their offspring is unlikely to be very useful. The kale seeds I received represent a different philosophy.
The grex originated in a rare flowering of Daubenton’s perennial kale, pollinated by a number of adjacent brassicas. Since then enthusiasts have been breeding in as much diversity as they can. The idea is that individual growers can then select for whatever characteristics they like, according to local conditions and personal preference. If the long-lived characteristics of Daubenton’s are also selected for, this could eventually yield a galaxy of perennial kales, from super-cool Tuscan types to my personal hope, a perennial Pentland Brig.
Here you can see the diversity in a single row of OP kale, showing variation in leaf size, form, texture, coloration and yield. In the next generation, I’ll be selecting from this variety on five criteria: leaf size, yield, tenderness, funkiness and lifespan. Perennial kale is a great candidate for this approach. Uniformity isn’t particularly critical in kales: there are some of these plants that I won’t be breeding from, but none that are a waste of space.
Furthermore, a plant with a particularly good combination of qualities can then be propagated vegetatively by cuttings so that it is preserved. A number of other crops also have these characteristics: mostly ones which propagate by seed but also by bulbs or tubers. Most importantly, there is the potato. We usually buy ‘seed’ potatoes in bags of tubers from a single clone, but they also grow perfectly well from the seeds contained in the little tomato-like fruits that you may see on the vines. If you get a good one, it can then be propagated indefinitely from the tubers in the normal way. One variety I’m growing from is Magic Dragons, a very blight-resistant line that I was sent by Tom Wagner. The Kenosha Potato Project is an amazing network of true potato seed enthusiasts.
The alliums are another group with lots of potential. The problem with many asexually-propagated vegetables is that they slowly lose the capacity to produce seed at all, meaning that opportunities for future breeding are lost. Sometimes they can be coaxed back into seeding, as in the work that Kelly Winterton has done on potato onions (which are probably the same thing as shallots).
But why would you want to do this? Aren’t there proper plant breeders out there, honing the perfect varieties for us? Well yes, there are, but they can never hope to produce the range of locally-adapted varieties that an army of amateur enthusiasts can. Also, the nature of their trade means that they have to actively breed diversity out of their seed lines so that they are uniform and stable. Where this is a virtue, I’m quite happy to rely on the big guns to do the work, but where it isn’t, I’d rather have a joyous riot of diversity in my garden.
Big plant breeders are currently trying to claim rights far beyond a just reward for the work that they actually do, patenting not just individual mutations but whole broad characteristics of crop plants. This stifles seed sharing and the genetic heterogeneity that is essential for future resilience. The Open Source Seed Initiative is one response to this. Getting maximum diversity into seed lines is another, as explained in the excellent article Linux for Lettuce. Above all, it is simply so much more fun. The anticipation, interest and potential in my OP kale are simply so much higher than in any ‘clean’ variety I have ever grown. I’m now taking this approach to all the legumes and leaf crops that I grow too. I’ll leave you with a few more of those kales…
Winter harvests 2015
A very mild end to 2014 in Aberdeen meant that a lot of my root crops didn’t get harvested until the end of December and I am still digging some up now.
The late frosts were ideal for the oca, which only starts to tuberise around October and therefore had a good long season. In a bad year here frosts can cut it down before it produces any tubers at all. As well as the ones I planted, I had a crop of volunteer oca coming up where I had them last year. Interestingly, they had the same yield as the planted, manured crop and bigger, better tubers. I suspect that this is down to the wider spacing and resulting larger individual plants. They were also less chewed-on by beasties in the soil, presumably due to the lack of compost. I’ll try to recreate these conditions with my deliberate crop this year. One surprise when I dug up my oca was that one tuber on one of the plants was almost white, compared to the pink/orange colour of the rest. I’m told that such colour sports are quite common in oca, and look forward to propagating my very own strain!
Roots, tubers and swollen stems form a pretty large part of my diet in winter. I counted twelve in last night’s stew, some from store, but mostly just dug up: turnip, sweet cicely, potato, oca, yacon, carrot, parsnip, salsify, Hamburg parsley, udo, Chinese artichoke and skirret. Such a variety gives a wonderful flavour even with the simplest of cooking methods. Two of the above perhaps count more as spices than as main ingredients: the sweet cicely and the udo. Sweet cicely root has a strong aniseed taste which is overpowering raw or in bulk, but adds a great flavour sliced thinly and sparingly into any dish. I dug up a mature sweet cicely of maybe four or five years’ growth this autumn, being as careful as I could not to break the root. It finally snapped off at about one inch in diameter. The part I dug out was over a metre long. It would have been interesting to have excavated the last section to find the total length, but I had reached the limit of my spade! Perhaps not surprisingly, this one root has met all my sweet cicely needs so far this winter. It has stored extremely well simply kept in a cool place (being far too large for my fridge).
Udo (Aralia cordata) root is similarly best used sparingly but at least it is easier to dig up. It has a similar taste to the spring stems, with some slightly harsher notes mixed in. The real gourmet food available from udo at this time of year is the underground stems that it puts out as runners to spread itself. Cooked briefly they have a melting texture and a taste very similar to the spring shoots.
There were a few other rooty experiments during 2014. Burdock (Arctium lappa) root cooked as kinpira gobo was utterly delicious, but I have had to restrain myself as I would like to grow most of my roots on for seed. I often have trouble getting bought burdock seed to germinate and my usual solution for that is to produce seed myself so that I know it is fresh. By contrast fennel roots were a disappointment. Fennel (Foeniculum vulgaris) self-seeds itself freely around my allotment and its roots are edible, so I had high hopes, but they turned out to be extremely bland and boring, with none of the flavour of the leaves or seeds. One breeding task I set myself this year is to see if I can get my very hardy and vigorous herb fennel to cross with the bulb-forming Florence fennel. They are just different selections of the same species so how hard can it be?
Skirret – Sium sisarumAnother root with lots of potential is skirret (Sium sisarum), another carrot relative. Instead of the traditional single root it produces a massive cluster. This makes peeling a job only for the seriously dedicated, so I always use them with the skins on, which fortunately is fine. They have a deliciously sweet, carroty taste and a nice floury texture after just a few minutes cooking. Cooked longer they will disintegrate entirely, which can be useful for flavouring soups or stews. A cluster like the one above will grow from a small division if it is given a rich, moist soil. I clearly didn’t give it quite enough moisture this year as my roots had a thin, woody core, which they develop in dry soil. This can be worked round by using the roots sliced thinly, but this year I have dug them a sunken bed next to the water butt and dug in plenty of leaf mould, as I feel that this is a crop really worth getting right.
Chinese artichokes (Stachys affinis) also did well. For anyone who hasn’t tried these before, they have a mild flavour and a nice crunch and look almost exactly like big, fat, white grubs, to the extent that I managed to kid my flatmate on for a good while that that was what was in the evening’s stew. I also tried rough bugleweed (Lycopus asper), which is similar to Chinese artichoke in many ways, but to my mind inferior in both taste and texture.
Two more tubers, both in the bean family: regular readers might remember my struggling hopniss (Apios americana) tuber, which every year manages to scrape together enough resources to yield exactly one tuber at the end of the season. This year’s warm conditions allowed it to produce an unprecedented six tubers. Needless to say, these are far too precious to consider eating: with such an abundance I’ll be able to try a few more ways of growing this fascinating plant before I finally admit that it is too cold for it here. That point may come a little sooner with talet (Amphicarpaea bracteata). Strictly speaking talet doesn’t produce tubers but beans growing on underground stems which serve the same function. Since growing underground poses certain challenges to fertilisation, the beans produced in this way are asexually produced and, in good conditions, the plants also bear an above-ground crop of seeds in the usual way. Unfortunately, in my case I ended up with vastly less reproductive material than I started with. I began with a good source of seeds, sourced from the northern end of talet’s range in Nova Scotia, and a handful of tuber-beans. Although I felt rather like Jack planting these, magic beanstalks did not result. In a wide range of planting sites, including a pot in my balcony, my allotment and another site further inland which experiences slightly hotter summer conditions, the plants grew very weakly and at the end of the season careful digging managed to produce only two underground beans. I’ll do what I can with these next year, but more in hope than anticipation.
Moving above ground, a few hardy plants are still giving me fresh veg straight from the garden despite the sub-zero temperatures. Daubenton’s (perennial) and Pentland brig (biennial) kale are still performing well. Nine-star perennial broccoli also produces tender and sweet leaves that are excellent as a winter kale, despite being a cauliflower than thinks it’s a broccoli! Leeks (Allium ampeloprasum var. porrum) are for me the undisputed king of the Scottish winter garden. I only grow winter varieties such as Bandit and Musselburgh, the latter being a traditional variety that has never been beaten. There are so many other alliums available in the perennial garden for the rest of the year that there is hardly any need for another, but in the depths of winter leeks really come into their own, laughing at freezing temperatures and even continuing to put on a little growth, with a flavour that for me beats even that of cultivated onion (Allium cepa). Garlic (Allium sativum), elephant garlic (Allium ampeloprasum var. ampeloprasum) and Babington leek (Allium ampeloprasum var. babingtonii) are all putting up shoots that could be cut and harvested, although apart from some garlicky-tasting leaves from the elephant garlic I mostly leave these for spring and summer harvest.
Having read Stephen Barstow’s book, I plan to do a lot more with indoor sprouting of seeds and forcing of roots for greens next winter. Since Stephen managed a salad with twenty different plants this week despite the 24-hour darkness of a Norwegian winter outside, he clearly knows what he is talking about! As an indication of what can be done, a salsify root left in the fridge while I was away over Christmas took matters into its own hands and produced a large head of succulent, white leaves. Finally, despite the sub-zero temperatures outside, one plant is already beginning to sprout. The leaves of alexanders (Smyrnium olusatrum), picked just as they emerge and slowly fried in butter, have a delicious taste that gives a promise of a new season to come.
Daubenton’s kale – growing and cooking
Daubenton’s kale (Brassica oleracea var ramosa) is a perennial vegetable that seems to have everything going for it: tasty, hardy, productive and easy to grow.
I also grow nine-star perennial broccoli (Brassica oleracea botrytis aparagoides – actually a sprouting cauliflower) which is often touted as a perennial, but really it’s just a biennial that manages to hang on for a few more years if you zealously remove all the flowers. Daubenton’s, on the other hand, is the real deal, a perennial kale that usually lives for 5 or 6 years.
It seems that a lot more kales used to be perennial, but Victorian seed companies selected for biennialism in order to be able to sell the same variety year on year. A few old varieties have hung on by being passed from gardener to gardener, leading to a plethora of names such as Ragged Jack, tree collards, Woburn kale, Taunton Deane and many others which may or may not be the same as each other. Worse, some biennial varieties share a name with perennial ones having been bred from them. My all-time-favourite biennial kale is Pentland Brig; there’s a rumour of a perennial version out there which I dearly hope is true. In Germany there’s an ehwiger kohl (‘everlasting kale’ or, as Google Translate charmingly puts it, ‘eternal carbon’).
The bargain that Daubenton’s makes for its long life is that it is lived in complete celibacy. It is hardly ever known to flower [but see The Joy of Promiscuity], which means that it doesn’t exhaust itself, but adds a problem for the gardener: no flowers means no seeds, perhaps giving one reason why it is so rare. Fortunately, it is extremely easy to propagate from stem cuttings, particularly if you break off branches near the base. You’ll find some knobbles which are incipient roots. At most times of year you can plant cuttings or put them in water and the roots will start to grow. In autumn, Daubenton’s undergoes a brief hiatus when it slows its growth and sheds a lot (but by no means all) of its leaves. I’ve noticed that at this point its capacity to grow from cuttings is much reduced, so if you have failed to get them to root at this time of year, don’t give up. Another method is to layer branches by bending them down and burying a section. Over time the buried section will develop roots and make a new plant.
I got my first Daubentons in 2009 from Pépinière Eric Deloulay in France. He’ll deliver to the UK but there doesn’t seem to be an English version of the website, so you’ll have to scrape your secondary-school French back together or Google Translate it and run the risk of buying some eternal carbon by mistake. I got two versions, one green one with a red tinge to the leaves and another, variegated, one with larger leaves. The Agroforestry Research Trust now sell the non-variegated variety and Pennard Plants have both kinds. Cotswold Garden Flowers sell the variegated form (plants simply disappear from their list if they are sold out, so if it’s not there, that’s what happened). I’m often asked about suppliers in the US and Australia. I haven’t managed to track any down, but if you’re a supplier, or know of one, anywhere outside Europe, let me know and I would be happy to put up a link. If you are in the States, you might like to look at the ‘Kosmic Kale’ supplied by the Territorial Seed Company. This claims to be a new variety but it certainly walks and quacks like variegated Daubenton’s.
My original plants have now all died out but they have given rise to several generations of successors. A mature plant typically makes a dome about one metre high and wide and lasts for about 5 years. Winter hardiness seems to reduce with age and I usually lose some older plants over winter, but taking cuttings or allowing plants to self-layer seems to reset the clock. The worst cold my plants have had to face was -15°C one year, which they did with aplomb.
I have planted cuttings in various positions in sun and part shade (under an apple tree) and they have thrived in all of them. This ability to tolerate shade makes them ideal for my forest garden set up. They are also said to be very tolerant of soil conditions.
I use Daubenton’s pretty much wherever I would use an annual kale, in soups, stews and stir-fries. In summer I mostly use it as a pot-herb, usually in a 50-50 mixture with sea beet. The kale takes longer to become tender than the beet, so you have to make sure it is cooked enough. In winter the leaves become sweeter and tenderer, enough that I start to use them in salads too. They are also ideal for kale chips (i.e. crisps).
Incidentally, Daubenton’s kale was named after the great French naturalist Jean-Louis-Marie Daubenton, a man who has had to suffer the posthumous indignity of English speakers constantly sticking an apostrophe into his name in order to make it look more French, so you’ll often find the plant referred to as D’Aubenton’s kale or even chou D’Aubenton. It’s also sometimes seen as ‘Dorbenton’, which seems to be an English phonetic spelling.