Growing and eating skirret

Never mind the Lost Crops of the Incas, skirret (Sium sisarum) seems to be the Lost Crop of the Europeans. Based on my experience, it’s high time it was rediscovered.

Originally from China, skirret was clearly well established in Europe by Roman times. It was a favourite of the Emperor Tiberius, a man who, don’t forget, could have pretty much anything he wanted for his table. He liked it so much that he demanded it as tribute from the Germans. It remained widespread and popular into Tudor times and then… where is it now?

Two crops of European empires may have displaced skirret. The first was the potato. Skirret is a starchy root, a useful staple, but nothing like as productive as the potato (what is?). The second was sugar cane. One of the most striking characteristics of skirret is its sweetness: even the name comes from a Germanic origin meaning ‘sugar root’. Before ubiquitous sweeteners, this would have made it extremely attractive, even to greedy Roman emperors. Whatever the reasons, skirret faded away from gardens, tables and popular consciousness. I’d say that it has several characteristics that make it worth revisiting.

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First up, skirret is delicious. It has a floury texture, a little like a potato, due to the high starch levels. Its taste is unique, but vaguely carroty, not surprisingly as it comes from the multi-talented carrot family (Apiaceae). It needs very little cooking. A minute or two’s boiling is enough, or you can briefly pan fry it. Being from Central Scotland, I have of course tried deep-frying it and can report that it makes a passable chip, but scoring higher in taste than texture when cooked this way. Wikipedia has an entertaining section on skirret recipes through the centuries. You might also like to try this recipe from the Backyard Larder Blog for skirret pasties – it also uses several other forest garden staples.

Secondly, skirret is quite easy to grow once you know how. Unlike most of its vegetable relatives it is not a biennial with a single taproot but a perennial that produces a whole shaggy bunch of roots. A dormant skirret plant can therefore be lifted, divided and replanted like any clump-forming perennial. Grown from seed, skirret produces a single ‘crown’: several shoot buds around the base of a stem, with a cluster of roots attached. Grown on, this crown will divide to form a clump made from several crowns. The clumps are easy to tease apart into individual crowns again. A cluster of roots will consist of several that are worth picking and a good number that aren’t, so my harvesting method is to dig up the clump, snip off the roots that are worth having, separate into crowns and replant. This leaves the plant with the maximum amount of resources for a good start the next year.

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A skirret clump

Thirdly, skirret ought to be an easy crop to improve. The combination of annual seed production and clonal propagation by the division of clumps means that new varieties are easy to produce and then maintain. The plants that I have grown from seed show considerable variation in root number, thickness, length and quality. I’d like to see skirret selected to produce fewer, fatter roots with smoother skin (cleaning skirret is something of a faff as the wrinkled skin tends to hold the dirt and require a good scrubbing).

One drawback to skirret is that the roots can have a woody core which cannot be softened by any amount of cooking and which is not particularly practical to remove. Guides suggest that this is a problem of young plants that goes away on older ones, or that it is caused by a lack of water while growing or that it is under genetic control and varies from one plant to another. My experience suggests that all three are true, which means that a combination of breeding and correct cultivation should be enough to solve the problem.

Starting skirret from crowns may be easy, but to get a crown in the first place you either have to shell out a fair bit of money or you have to start from seed. Skirret is not the easiest to grow from seed as like many of its relatives it needs a period of winter cold (stratification) to encourage it to germinate. If it is anything like most apiaceae the seed will lose viability quite quickly, so it is a good idea to source current-year seed in autumn and start stratifying straight away.

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A single clump separated into crowns. The labels are to keep track of individual strains for plant breeding purposes.

For cultivation, skirret seems to like moist, free-draining soil in full sun. It’s said not to like hot weather but this isn’t a problem that I experience much. I’d advise growing it in rich, well-fertilised soil as a poorly fed skirret will produce thin roots that aren’t worth harvesting. Mature crowns need to be spaced at 30cm or more. Giving it a mulch is a good idea to help keep moisture in and suppress early weed growth. I have mine planted in a bed with compost dug in and a mulch of leaves over the top. It will grow up through the mulch and require little to no weeding as its strong growth suppresses weeds later in the season. Unless you want to try your hand at seed production, remove the flower stems to divert more resources to the roots. Regular watering will help to avoid the dreaded woody core – I have mine planted right next to my water butt so that I have no excuse for forgetting. Skirret can be left in the ground until needed: towards the end of the season, you might want to mark where the plants are as there can be little sign once the leaves die down!

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.

oca crop

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).

sweet cicely root

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

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.