Growing and eating silverweed

Silverweed has a long history as a cultivated crop. It was sufficiently important, in the landscape-scale agro-ecology of the pre-colonial Pacific North West, that access to good patches was controlled by law. Closer to home, Alexander Carmichael says in the notes to the Carmina Gadelica that silverweed root (brisgean) was much used in the GĂ idhealtachd before the potato was introduced. He says that it could be traded, ‘quantity for quantity’ with corn and meal, suggesting that it was equally valued nutritionally. It was considered palatable and nutritious and eaten boiled or roasted or dried and ground into meal for bread and porridge. I mostly eat it boiled and find that it has a rich, creamy taste and texture.

One eye-catching claim made by Carmichael is that at Lag nan Tanchasg in Paible, North Uist, ‘a man could sustain himself on a square of ground of his own length’ by growing silverweed. Unfortunately he makes no mention of cultivation methods, but I suspect that he is talking about a lazy bed system, in which a raised bed is heavily mulched with seaweed. This would make sense both as a way of growing heavy yields of, well, anything, on Uist (and was later used there for growing potatoes), and also because silverweed is well adapted to growing on the seashore and is often found there. Like many species adapted to growing on shifting sediments, it spreads strongly via runners, which help it to bind the soil together and adapt quickly to disturbance. It’s a habit which has helped it adapt to other, novel habitats, such as the frequently-disturbed, heavily-salted margins of roads.

Variation between clones: silverweed…

…and not-so-silver weed

It’s also a habit which makes it, as anyone who has tried will know, difficult to replicate past cultivation methods in an ordinary garden. It will take over any veg bed it is planted in in short order. It will also naturalise happily in grass, but then it becomes very difficult to dig out the starchy roots which are its main edible part. A further complication, if anyone was really serious about adapting this plant to cultivation, is that it’s hard to maintain and breed separate lines of a plant that is hard to contain as an individual even in a pot, never mind in a patch of soil.

This might explain why, despite having been interested in silverweed ever since I first tasted its roots, I haven’t made much progress in fitting it into my garden. However, I did make one useful discovery recently which should make the task somewhat easier. I have a number of individual clones, collected from around the country, which I keep separate by growing in buckets (escaping from a bucket is nothing to this Houdini among plants, but you can thwart it by winding its runners around inside the rim of the bucket, making sure they never touch the ground). One winter I tipped out one of these buckets, and discovered that the thickened roots had almost all formed right at the bottom – making it easy to nip off the best ones to eat. I then put some compost in the bottom before putting the whole mass back in on top. They respond well to this treatment, and also become more willing to produce seeds, which I plan to use to start new pot-colonies.

brisgean
seeds

It’s not really in the spirit of forest gardening, in which the plants are meant to be more integrated than this. It’s also a challenge with other shifting-sediment plants like asparagus, which rely on their environment to deal with competitors and are intolerant of any competition. However, I can picture an analogue of the lazy bed, with a well-edged raised bed, regularly topped up with the abundant compost produced by a forest garden. This wouldn’t have the bottom-of-the-bucket effect but would probably create a soil loose enough to be dug easily.

Incidentally, I haven’t been following my usual practice of giving Latin names alongside the English ones in this post. This is because the naming of silverweed is, frankly, a mess. It’s an aggregate species which can be divided into many or lumped into one according to taste and fashion, and systematists can’t even agree on which genus to place it in. It is (probably) called Potenialla anserina today, but the genus name Argentina is also commonly used.

Silverweed flowers by S. Rae from Scotland, UK, CC BY 2.0 via Wikimedia Commons

Honey under ground
Silverweed of spring.

Honey and condiment
Whisked whey of summer.

Honey and fruitage
Carrot of autumn.

Honey and crunching
Nuts of winter
Between Feast of Andrew
And Christmastide.

Carmina Gadelica, from translation edited by CJ Moore, Floris Books 1992 p366. Thanks to Alison Tindale of the Backyard Larder for putting me on to this reference.

Back to my roots (and tubers) – 2016

This post (a catch up on my experiments with all things subterranean) is a little later than I expected. Many roots and tubers are not lifted until after the first hard frost. This can hit in October or even September in Aberdeen, but this year there was nothing significant until January, so many plants just kept on growing. The other factor is that I am still recovering from a slipped disc I suffered last spring, which means that I have to ration my effort in the garden and watch the heavy digging.

Now, however, the harvest is complete and the results (as well as the roots) are in.

Some plants have by now become staples of the forest garden and my winter diet, including oca, yacon, skirret, Chinese artichokes and TPS potatoes. The slipped disc meant that some of these had to cope with very late planting and considerable neglect over the year. In some cases that meant that I only just scraped through the season with my planting stock intact. Fortunately, however, roots and tubers are forgiving plants. They carry generous reserves that allow them to grow quickly and smother annual weeds, so some of them did quite respectably all the same. Roots that I allow to self-seed in the garden, such as parsnips and salsify, did so with little fuss.

These are exciting times for the breeding of many root crops. My oca and yacon both flowered, but far too late in the season for seed, so I think I’ll have to leave those projects to collaborations with a more southerly distribution, such as the Guild of Oca Breeders. Yacon was once thought to be sterile, but the Cultivariable seed company in Washington State has managed to make a range of crosses (I can highly recommend Cultivariable as a supplier of most of these plants). Yacon seems to be an obligate outcrosser – that is, it needs two or more varieties grown together to produce fertile seeds. Anyone with two varieties of yacon and enough sunshine can join in the fun.

I had more luck producing potato seeds. Potatoes also struggle to fruit in time here, but the fruits can be ripened up on the windowsill like tomatoes and will reliably produce viable seed this way. It helps that TPS (true potato seed) varieties can be stunningly blight resistant, meaning that they get the chance to keep on growing right up until the frosts. There’s more on why you might want to grow potatoes and many other things from diverse seed in my post here.

burdock burrs

burdock burrs

Another reason I find for producing my own seed is that a number of root crops can be quite difficult to grow from bought seed as they do not store well and can have tricky germination requirements. My usual way around this is to grow my own, giving super-fresh seed that I often sow in autumn rather than spring. I managed to do this with burdock (Arctium lappa) this year. My saved roots sprouted to nearly 3m high and produced an abundance of the spiky seed heads that were the inspiration for velcro. The only drawback was that they tried to recruit me as a seed vector any time I passed. Burdock seeds may get so lodged in the coat of an animal that they stay with it until it dies, giving the germinating seed exactly the rich, fertile conditions that it likes. I love my plants, but that’s where I draw the line! Seeds that I collected and sowed in autumn are already germinating despite the snow on the ground this week, so I am already looking forward to a summer of kinpira gobo.

A plant that I have similar problems in getting viable seed with is Hamburg parsley so I am trying the same approach this year, with several choice roots saved for seed production. Turnip rooted chervil (Chaerophyllum bulbosum) benefits heavily from this approach too – I’ll post more about this plant soon.

Going back to the Andean root crops, I had promising results with two more. One that I tried for the first time was ulluku (Ullucus tuberosus) – also known as papalisa, ulluco, milluku, chugua and ruba. Ulluku produces both edible leaves and tubers that taste remarkably like beetroot. It put up with severe neglect and still cropped reasonably well for me. Undoubtedly the most striking feature of ulluku is its looks: the tubers come in a dazzling array of buttercup yellows, rose pinks, lurid magenta and porcelain white. Digging them up is like unearthing semi-precious stones. On the downside, centuries of vegetative propagation have left many lines of ulluku virus-ridden and reluctant to produce seed. Yet again, Cultivariable is having spectacular results in coaxing this species back into reproductive life, so I think we can expect to hear much more about this species in the next few years, with cleaned up tubers and new varieties.

Ulluku

Ulluku – yellow variety

The other new South American is mauka (Mirabilis expansa). Mauka is described on Wikipedia as growing at “cold, windy altitudes” in the Andes, which sounds just ideal to me! My mauka seeds rather surprised me by germinating immediately when I put them in the fridge to stratify, so I now have six little mauka seedlings growing away, just waiting to experience the cold, windy altitudes of Scotland (i.e sea level).

I have spent a while gathering plants of silverweed (Argentina anserina) from different locations and planting them in large pots outside. The reason for this curious behaviour is that silverweed is a very strong spreader, so without control you will tend to have just one extensive clone in your garden. I’d like to get seeds of this plant in order to try breeding it, since it is delicious and locally well adapted, but has the drawbacks of thin, straggly roots and that agressive spreading habit. A non-runnering variety would be favourite! I wasn’t able to collect any seed last year, but the plants all look healthy and I hope for better results this year.
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Finally, a hill of beans. The bean family (Fabaceae) contains a number of species with edible roots, including talet (Amphicarpaea bracteata), hopniss (Apios americana), aardaker (Lathyrus tuberosus) and cairmeal (Lathyrus linifolius montanus). With me, the Lathyrus species have been disappointing: my aardaker has almost died out, while the cairmeal is growing quite cheerfully without producing anything that could be seriously regarded as an edible root. Neither the talet nor the hopniss made it out of the greenhouse and into the ground this year. Both seemed quite happy with this arrangement: both flowered and the talet produced seed. On the other hand, the hopniss produced only one tuber per tuber and I couldn’t find any of the subterranean beans that are meant to be the main yield of talet. Both are now lying low and, I imagine, dreaming of better weather and better health on the part of their gardener for the year ahead. Me too.

Previous posts relating to roots:
Winter harvests 2015
Back to my roots (and tubers) – 2014