Sizing up the Skirret

Skirret (Sium sisarum) is a perennial root vegetable with long white roots. It seems to have been a very popular vegetable in Europe in the sixteenth and seventeenth centuries. I've also often read that it is still commonly eaten in parts of Asia. The references aren't more forthcoming about this so I'd be very pleased if anyone can give me fuller details.

young skirret plant
Young skirret plant

Most sources say the introduction of the potato lead to the decline of the skirret in Europe. I have to say that this rather baffles me - a skirret and a potato are not terribly alike; if I had one I don't think I'd stop eating the other. As well as being long and slender, skirret roots are distinctly sweet. Skirret is zuckewurzel in German, meaning sugar-root, and was once investigated by the German chemist Andreas Marggraf in his search for plants, other than sugar-cane, that might yield sugar. Skirret ranked below white beet but above red beet in sugar productivity.

Perhaps skirret's multiple long slender roots just fell out of favour on grounds of fiddliness. I'm interested in finding out how to grow skirret roots which are fat enough to be satisfying to cook. After all it defeats the object to find vegetables which take little effort to grow if they then take longer to prepare for cooking.

I think I must have come by my first skirret in 2011 by buying a plant from Poyntzfield Herb Nursery. I know I just had one plant and, having read that it will grow in semi-shade, planted it on the less sunny side of the edible hedge in the herby bit of the allotment.

Researching skirret in books and on the internet has led me to the conclusion that this really is a plant to keep an open mind about. Reports have furnished me with a set of conflicting cultural notes, i.e. that the plant is best in full sun - or full shade; that the plants should be planted a few inches apart - or two feet apart; that one gets better results from seed - or from crown divisions. It is certainly worth doing one's own investigations. But at least most advice agrees that skirret will produce the longest, thickest roots in moist, light soil. The soil on the allotment is not ideal for skirret being a fairly heavy clay that has varied from very wet to very dry in the last few years. It was probably fairly moist for most of 2011 when I dug up the roots below - but they were pretty weedy specimens, and after a quick nibble, which confirmed their sweetness, I promptly planted them again to grow bigger.

one year skirret roots
One year skirret roots

I dug up the same plant a few weeks ago. It is on the left in the photo below with a younger plant beside it produced from an offset of the older plant.

three year skirret roots
Three year and two year skirret roots

The roots were still rather thin and and a bit stringy. I scrubbed some up and boiled and mashed them. They were sweet and tasty but spoilt by having an occasional woody pith and too much fibrous skin (they were too thin to bother peeling).

I also planted some young plants early this year. If my memory is right these had been grown on in pots for a year from seedlings kindly sent to me by Rhizowen of Radix. I set these out in full sun, widely spaced, kept them well weeded and planted a ground cover crop of wild strawberries around them.

skirret bed
Skirret bed

Yesterday they all came out of the ground. They are said to be even sweeter after a few frosts but I was impatient to see how they had done. With apologies for the fuzzy picture, you can see the results below, roughly graded for increasing size from right to left.

two year skirret roots
Two year skirret roots

The photo doesn't quite do them justice as they were a bit beefier than they look here. There was certainly an increase in root diameter over my previous efforts with the thickest root being 15mm wide. I was pleased about this especially given the exceptionally dry summer we have had (and the plants have had very little in the way of supplementary watering). But the roots were still rather short, presumably a result of the heavy soil, and were somewhat crooked.

Clearly I have a way to go to get to skirret Shangri-la. For something to aim for I can take a look here to see Norris Thomlinson's skirret roots in Portland, Oregon; here for Ian Pearson's roots on the Isle of Wight; here for Ivan Day's roots in Cumbria (along with wonderful images of his seventeenth century skirrit pye) and here for James Wong's impressive effort in London. I've asked James Wong on Twitter how he managed to get such long, straight, white roots so if he spots the tweet and answers me I'll pass on the tips! But I expect he would answer that he grows them in a deep, moist, sandy soil.

It may be possible to buy a superior skirret variety but I don't know of any UK source, just Perennial Pleasures Nursery in Vermont which is recommended by Eric Toensmeier. So I did a bit of selection of my own, harvesting the thickest of the skirret roots and dividing just the most promising of the clumps, replanting the offsets in soil augmented with compost. (A good bit of sand would have been good in there too - so I'm now tempted to buy some sand and redo the job!) I carried out my plan to team them up with silverweed (Argentina anserina) for an edible ground-cover and I intend to mulch them particularly well to retain moisture. I've also put the plants rather closer together this time as the clumps stay quite slender. This replanting is ideally done in early spring when the plants have plenty of time to grow away but I think doing it now will work fine too. It is certainly convenient to replant at the same time as harvesting. There is also no need to divide clumps if you don't need to multiply the number of plants; just harvest the biggest roots and replant the clump.

skirret offset
Skirret offset

Skirret roots will be amongst the roast vegetables for tea tonight - I will report back on the result!

Well I decided to use Ivan Day's method of boiling the roots before peeling them. I boiled them for 8 minutes which was a bit too long considering that I was then going to roast them. I'll cook them for about 4 minutes next time. But this mistake clearly revealed why they are likened to potatoes - peeling the overcooked roots resulted in a creamy mush on my fingers exactly like mashed potato in consistency.

unpeeled skirret roots
Skirret roots - washed but unpeeled
skirret roots among vegetables for roasting
Skirret roots amongst vegetables prepared for roasting

The roasted skirret roots were delicious and got a very enthusiastic thumbs up from Stew (who in his own words is "someone who is not a natural lover of weird stuff"!)

roast skirret and other vegetables
We had the roast vegetables with rice and veggie sausages.

(Skirret update 1 here, 2 here and 3 here.)

N.B. I sell a range of perennial vegetable plants on my website.