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!

 

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Perennial wall rocket

I first came across Diplotaxis tenuifolia at a seed swap on my allotments site. It was labeled ‘wild rocket’ so, thinking it was nothing more than a wild version of the familiar salad leaf (also known as rucola or arugula), I sowed a row and more or less forgot about it. When it grew, there was nothing to make me change my mind. Its attractive, lacy leaves looked like a finely-cut version of rocket and that distinctive peppery taste that you either love or hate (I love it) was there.

But then it did a very un-rocket-like thing. It kept on growing. And growing. The frustrating thing about ordinary rocket is that it just wants to flower and seed, so the period during which it can be bothered producing leaves is little more than a month. My new rocket flowered profusely with lemon-yellow crucifer flowers that the hoverflies clearly loved, but it also went on and on producing new leaves, eventually making a bushy, if floppy, plant about a foot high. Finally, I made some discreet inquiries into its parentage.

Image by T. Voekler on Wikimedia Commons

Wild rocket, it turns out, is just one of the names of D. tenuifolia, along with sand rocket, sand mustard, Lincoln weed and perennial wall rocket. These give a clue to its habitat. It likes a free-draining soil, be it sandy or rocky, and doesn’t need much in the way of water or nutrients. Ideally for my forest garden setup, it will also tolerate some light shade. It is also perennial, meaning a much longer period of leaf production than annual rocket. It is still growing in my garden in Aberdeen, despite several heavy frosts, and last year it went on until the first snows. It is also very early to come back into production once winter is over.

The taste of wall rocket is much like that of its annual cousin, but with a hint of cabbage and more of a kick. The leaves get stronger as they get older, but there is a continual production of fresh leaves, so I don’t find this matters much. You can cut the plant down to encourage a bigger flush of new leaves. If you have lots of older leaves, you can blanch them in boiling water for about 30 seconds which reduces the heat a bit. Cooking them for longer than this isn’t recommended as they lose their flavour entirely. My favourite uses are in salads, sprinkled on pizzas once they come out of the oven and as a topping for pasta sauces. You can also make soup with them in the same way as you make watercress soup.

The final surprise that wall rocket had for me came when I tried to move a couple of plants. They had deep, fleshy tap roots, which means that they probably act as dynamic accumulators in the garden ecosystem.

Eating the shrubbery

It is surprising how many good edible plants are grown purely as ornamentals and their food wasted. When tomatoes were first introduced into the United States, they were widely regarded as poisonous and grown mostly for decorative purposes. The same thing goes for a lot of common ornamental shrubs. All the plants below would happily take a place in the forest garden or allotment, but perhaps in this case you could save some space and just raid the nearest shrubbery. Think of it as urban foraging.

Fuchsia
Fuchsia magellanica is the hardiest and most widely-grown fuchsia in Britain. It makes a large shrub to 2-3 metres. Here in the north-east the top growth is killed every few years in a hard winter, but the roots always survive and the plants soon recover. The milder west is more to their liking and I have seen them bidding to take over entire hillsides around Mallaig. The flowers are edible, if more for novelty value than taste, and very pretty. I like their Spanish name: pendientes de la reina – the queen’s ear-rings. These days there are many varieties available, but they are usually overblown and gaudy, lacking the elegance and beauty of the original.

Ripe fuchsia berries are very pleasant with a mild, sweet flavour. The biggest difficulty is picking out the ripe ones: unlike most fruits there is no great colour change, the ripe fruits are simply a little lighter, a little larger and a little softer than the unripe ones. It makes eating fuchsia berries something of an art, because the unripe ones taste horrible and catch at the throat, but you get your eye in after a while. Fuchsia berries are said to vary a lot in taste, although I suspect that some of the more negative descriptions (from ‘peppery’ to ‘petrol’) are the result of eating under-ripe berries rather than a true reflection of the ripe berry’s taste. I now make a point of tasting any fuchsia berry I see. They take extremely easily from cuttings so if you find a particularly nice variety, nip off a branch, put it in water and take it into your own garden (and send me a bit!).

Fuchsia magellanica

Gaultheria
Gaultheria is a large genus containing a number of ornamental shrubs. It now contains a number of species which used to be called Pernettya: these were the Southern-hemisphere species but since there was no consistent difference between them and the northerners they have now all been lumped together under Gaultheria. The nicest of them all is probably shallon (G. shallon), which I’ve written about before. The most striking is definitely prickly heath (G. mucronata), with red, white or pink berries that look like they are made out of polystyrene. It is difficult to imagine anything less edible looking, but in fact they are sweet and tasty. My girlfriend suggests that they could be used as healthy cake decorations. Like the fuchsias, Gaultheria species are variable and easy to propagate, so have the potential to be selected for the quality of their fruit. I recently found a variety of shallon with much fleshier berries than usual, so I plan to knock on the owner’s door and ask for some divisions of it some time.

Gaultheria mucronata berries

Berberis
Two species of Berberis are widely used as shrubs: B. darwinii (Darwin’s barberry) and B. thunbergii (Japanese barberry). Both have fruit that are too sour to enjoy raw, but B. darwinii berries are very tasty in a jam or jelly. Ciaran Burke gives a jelly recipe on Blooms ‘n’ Food. I think I prefer them as jam but I’m still experimenting. I’ll post a recipe next season.

Berberis darwinii

Japanese barberry is less useful, but you can juice the berries to make a lemon juice substitute. The Agroforestry Research Trust describe Korean barberry (B. koreana) as ‘the best edible barberry’ but Plants for a Future give it an edibility rating of 1 out of 5, so who knows?

barberries

Elaeagnus
Eleagnus is yet another varied genus of shrubs, including oleaster, silverberry, goumi, autumn olive and even Trebizond date. Mostly they are planted for their silvery, glossy or variegated foliage, but a lot of them have nice edible fruit too. Sadly this can be hard to come by: they need a pollinator and I’m not sure how far now far north they succeed in bearing fruit – I’ve found E. x ebbingei fruit in London but never in Scotland – but I think it’s worth checking out any bush you find.

Aronia
Black chokeberry (A. melanocarpa) is sometimes planted for its stunning autumn foliage, but it’s also a useful berry crop. Best in jellies and jams, it is rich in pectin and helps other fruits to set. The ones in my garden are growing happily and fruiting in a semi-shady position. They eventually grow to about 2.5m.

Aronia melanocarpa

Growing and eating garlic mustard

Garlic mustard (Alliaria petiolata) is a phenomenally successful plant. In its native range it grows from Ireland to China and from Africa to Scandinavia. In North America, where it is introduced, it is frankly rather too successful. Unpalatable to native grazers and naturally vigorous, it has become a serious invasive pest. As well as taking up space, it produces chemicals which interfere with the native mycorrhizae and sets a nasty ecological trap for a native butterfly. The caterpillars of some species of garden white butterfly naturally feed on toothwort (Dentaria). Unfortunately, garlic mustard looks very like toothwort and the butterflies are suckered into laying their eggs on it. When the larvae hatch, they are unable to digest the garlic mustard and soon die.

In its native range, garlic mustard (a.k.a. hedge garlic, Jack by the hedge and sauce alone) is much better behaved and an excellent candidate for the forest garden. Every part of it is edible, including roots, leaves, flowers and young seed pods. Flavour-wise, it does what it says on the tin, tasting like a cross between garlic and mustard. The roots are the hottest part, with a horseradish-like bite.

Garlic mustard is quite early to come into leaf and the youngest leaves are the mildest, so it’s a useful winter/spring green. As the year goes on the leaves get hotter and a bit acrid. I use them in salads and as a pot herb and often stick a leaf or two into sandwiches. There are much more imaginative ways to use it than this however. The one upside of the garlic mustard invasion of North America is that people have put some serious effort into finding ways to cook them in an effort to eat the interloper into submission.

Pesto seems to be a favourite, with the oily ingredients acting to balance the mustardiness. One recipe combines the pesto with green lentils and one particularly adventurous one throws in the roots for good measure. Garlic mustard roulade wins my prize for the most beautiful recipe and one person has even pickled the roots which must taste amazing.

Garlic mustard is a biennial, growing lots of leaf in its first year then running to seed in its second. It is a very vigorous seeder, so unless you want to end up feeling like North America, I suggest that you pull up most of the plants in the second year and just leave a few to provide the next generation. Be prepared to treat it as a weed in the rest of the garden and hoe it out ruthlessly if it seeds beyond where you want it. It is shade tolerant, growing in either full or partial shade (under a Victoria plum in my case) and not fussy as to soil.

Leycesteria

Some fruits are just meant for picking and eating, there and then, in the garden. Alpine strawberry (Fragaria vesca) is one, with its tiny, sweet, ever so slightly vanilla flavoured fruit that are doled out carefully throughout the summer. But the king of instant consumption has to be Leycesteria formosa, known to gardeners as Himalayan honeysuckle and to connoisseurs as the ‘treacle tree’.

No plant in the forest garden divides opinion like leycesteria: you either love or hate its startling mixture of molasses sweetness and bitter aftertaste. But however much you like it, don’t expect to take any home – the berries burst and splat so easily that storage is practically impossible.

Foods that you’ll never see on a plate have a special allure, but even some more common fruits are best eaten one by one, on the go. Blackcurrants and gooseberries, for instance, are at their best when they are far too soft and squishy to be picked and stored easily.

My treacleberries kicked off a conversation recently about planting food plants for children. Instead of coaxing kids to eat their five-a-day at the table, how much more effective to just plant a tangle of fruit in the garden and leave them to it, play and feeding all in one. I’m sure my love of fruit and foraging came from grazing on the yellow raspberries that lined the half-mile walk home from school. For maximum effect it is probably best to strictly forbid the kids to eat it.

When I first started in my allotment, my neighbour’s daughter used to beg to be allowed to come down and eat the sprouting broccoli. I think that’s when the full extent of how much more appealing self-picked food is to kids dawned on me. I’ve taken this insight into the park that I manage, which is stuffed with as much fruit as I can fit in. Leycesteria is an excellent option for a public food plant. It ripens its berries four at a time down the flower head, so it produces a regular supply rather than a glut that can be stripped. It is a very attractive, structural plant, sometimes known as ‘shrimp flower’ because of the look of their flowers, and any that don’t get eaten by people are made very welcome by the birds.

treacle tree

shrimp flower

Rhubarb and elderflower jam, and a surprise

Rhubarb is the one perennial vegetable that needs no introduction. Everyone must have a patch in the corner of their garden, even if it was planted by their granny and hasn’t been used since. It is long-lived and practically bomb-proof and it just goes on and on.

Most years my rhubarb patch doesn’t see a lot of use. One year I actually managed to set up a barter system with my local shop, swapping rhubarb and courgettes for bread, but then the ownership of the shop changed. More recently our community centre cafe has been using some of it, but I must confess to a bit of a history of neglect.

Fortunately, neglect is exactly what rhubarb thrives on and it points up a general advantage of perennial veg: if you don’t use them then they can store up the resources and become stronger plants. The yield is not totally lost as it is with annual veg.

This year, since so many of the fruits have done badly in the cold spring, I’m taking a little more interest in my rhubarb, so I called my mother, who is, in her own words, a ‘heavy user’ of the stuff. I remember most of her recipes from childhood: rhubarb crumble, rhubarb pies, rhubarb jams, rhubarb chutney and, best of all, a big stick of fresh rhubarb dipped in a bowl of sugar and eaten straight. There was even a surprisingly nice rhubarb wine.

To this day I don’t like crumble, but the rhubarb pies were wonderful, especially when left for a couple of days and served cold, with the rhubarb juices soaked a way into the pastry. However, it was the jam I wanted to try, particularly one of my mum’s specialities, rhubarb and elderflower. Here’s the recipe (adapted a little to cater for my preference for less-sweet jams).

rhubarb jam

Ingredients
3 kg rhubarb
1.5 kg sugar
10 elder flowers
Juice of 2 lemons
Makes 10 jars

Wash the rhubarb stems and cut off the leaves and the stem bases. Cut them into chunks about 2 cm long (use a sharp knife or you’ll find you don’t get all the way through the skin). Put the chunks into a bowl in layers, adding a little sugar over each layer and putting in the elder flowers head-down before doing the last layer. Pour the rest of the sugar over the top and leave overnight.

The next day you will find that the sugar has drawn the juice out of the rhubarb and the chunks are floating in syrup. Try not to let your children steal too many of these. Take the flowers out and steep them in water to make an instant cordial. Then boil up the jam in the usual way. Between the rhubarb and the lemon, this jam will set well so there is no need to overdo the cooking.

As this is a low-sugar jam, it is best kept in the fridge once opened, but it will store quite happily for years unopened. For better storage once opened, use equal amounts of rhubarb and sugar.

Elder is a tree with so many uses that I’ll have to give it a post of its own some day. It is so abundant that I prefer to forage it rather than have it take up space in my forest garden. I went down to our local park and selected ten choice blossoms; elder flowers have a rather nasty taste if you don’t get them at the right point, so each bloom got a sniff test to make sure it had that heady scent of summer. It’s the ones that look like they are almost over that are usually the best, not the pristine white new ones.

I also found a pleasant bonus while I was investigating the elders: they were full of jelly ear fungi (Auricularia auricula-judae, also known as Jews’ ears in a bit of traditional European prejudice). Jelly ears never found much favour in European cookery (one online description says that eating them is ‘like chewing on a piece of inner tube’) but Chinese cuisine has got a use for them: they are sliced thinly into stir fries to provide a mild flavour and a bit of a crunch. They can even be dried and rehydrated for the purpose.

Rhubarb in the forest garden

The scientific naming of rhubarb is a bit of a mess: you can choose between Rheum rhabarbarum, Rheum x hybridum or Rheum x cultorum. Rheum rhaponticum may refer to cultivated rhubarb or to another, closely related species. There are at least 2 other species of Rheum worth trying: Himalayan rhubarb (R. australe) is said to taste like apple and Chinese rhubarb or da huang (R. palmatum), like gooseberry. I’ve got both on order so I can let you know whether I agree.

Technically, it isn’t the stem of rhubarb that we eat but the petiole, the leaf-stem. The true stem only comes later, when the rhubarb flowers. A persistent myth about rhubarb is that it is poisonous after flowering: perhaps this came about from people trying to eat the flowering stem rather than the petioles. The part that definitely is poisonous is the leaf and there is another myth which says that you shouldn’t put them on the compost heap as they will poison it. In fact the poisonous compound is an acid which quickly breaks down in compost and is then completely harmless. A little-known fact is that you can also eat the flowers of rhubarb.

Rhubarb grows well in a forest garden. It doesn’t like full shade and shouldn’t be grown under another plant, but it is quite happy to be surrounded by taller plants which shade it for parts of the day.

Edible flowers

One of the most striking things about growing food with forest gardening is how many flowers end up on your plate. When you think about it though, the stranger thing is perhaps why this part of the plant has been neglected in our cookery for so long (apart from immature flowers like cauliflowers and artichokes). After all, plants are pretty keen on producing them and there is a massive industry dedicated to breeding and growing them for non-edible purposes.

Recently, the balance seems to have shifted and there is a bit of a fashion for eating flowers. There’s a good, comprehensive article on the subject here. However, a lot of this is driven by the search for novelty in fancy restaurants or is based on picking a few flowers off basically ornamental species to decorate a dish. There is a much shorter list of flowers that can really be considered as crops in themselves, either because they are so productive that they are worth growing as the main yield or because they are a by-product of a plant that is cropped for some other part. My short list is: day lilies, bellflowers, salsify, pot marigold, king’s spear, alliums, mallow, courgette, peas, runner bean, nasturtium, dandelion and (maybe) tiger lily and golden currant.

Pot marigold (Calendula officinalis)

Day lilies, salsify and bellflowers are the three most productive: best fried, steamed and in salads respectively. All three illustrate an important point about eating flowers: the more you pick, the more you have of them. For a plant, a flower is just a means to an end: getting pollinated and producing seeds. Once that has been achieved it rapidly switches its resources to the growing fruit or seed head and stops flowering, but if you frustrate its ambitions it will often keep on trying, sometimes for the rest of the year.

Pot marigolds (Calendula officinalis) are not bulk producers like the last three, but a small patch will produce a lot of flowers over the course of a summer. It is the petals that are used: they add a subtle but interesting flavour and an entirely unsubtle, cheerful colour to practically any dish. Perhaps they are best regarded as a herb. They are equally good raw in a salad or cooked in almost anything and unlike most flowers they keep their colour no matter how much you cook them. On top of this they are famously good for the health of the garden, producing chemicals that kill or repel little parasitic worms called nematodes. This combination of qualities, plus their relative ease of growing, wins them a place in my garden.

Allium moly

Golden garlic (Allium moly)

The alliums or onions are a group with too many edible species to even list. They are often grown for their leaves or bulbs but the flowers are usually edible too and they are often available when the rest of the plant has either died down or become woody. Chives (A. schoenoprasum) are one that I use a lot. Like all alliums, its flowers are borne on little stems radiating from a central point. The trick to using it is to get your thumbnail into this central point and nip it out, causing an explosion of little pink florets. Chive flowers are mild enough for salads. Wild garlic (A. ursinum) can also be used but has a much stronger, more garlicky flavour. Golden garlic (A. moly) hardly looks like an allium at all, with relatively few flowers per head and those bright yellow. The flowers add a sweet oniony flavour to a salad and the leaves and bulbs can be used too. Round-headed leek (A. sphaerocephalon) has huge, showy balls of edible flowers.

Common mallow (Malva sylvestris)

Common mallow has the advantage that it will grow in the shade. It’s an all-round useful plant that I’ve already written about here.

Across in the annual garden, courgettes (or zucchini if you prefer) are already moderately well known, especially frittered. Sometimes the baby courgette is harvested along with the flower but if you’re careful you can break the flower off the end of the fruit before it wilts, allowing you to both have your courgette and eat it(s flower).

Courgette (Curcurbita pepo ovifera)

Other annual crops that have unexpectedly edible flowers are mangtout peas, sugar snap peas and runner beans. The runners in particular are delicious and mine always produce far more flowers than they are capable of ripening into pods, so a little thinning does no harm at all. Don’t be deceived by appearances though: sweet peas (Lathyrus odorata) are not edible.

Pea flowers (Pisum sativum)

Another annual famed for its edible flowers is the nasturtium (Tropaeolum majus – a bit confusingly, Nasturtium as a Latin name refers to water cress, not nasturtiums.) Every part of the nasturtium is edible, with a hot, cress/pepper flavour. In fact they are too strong for me – the only way I like to use them is to pickle the seeds and use them like capers – but if you like a cress flavour then this is the plant for you.

I don’t plant dandelions (Taraxacum officinale) in the forest garden but, as you’d expect, I have them anyway. In fact they’re a fairly low level weed in the forest garden, so in contrast to my zero-tolerance approach in the annual beds I’m fairly lax about pulling them out, happy to make occasional use of the spring leaves and flowers in the meantime. Dandelion flowers should be cooked, preferably in ways that either exploit their bitterness or minimise it with a starchy component. Fritters and bhajis are good, or you could try the spicy fried dandelion recipe I found on a rather good blog by Ciaran Burke in Ireland.

Finally, a couple I haven’t tried yet but have high hopes for. Golden currant (Ribes aureum) has very pretty flowers which are said to be edible. It is closely related to buffalo currant (Ribes odoratum), which grows well here, so I’ve ordered some and expect them to thrive. Then there is tiger lily (Lilium linifolium). I am already growing this for its edible bulbs but I found out recently that the flower is edible too, with some very enthusiastic reports online. On the other hand, Plants for a Future list the pollen as poisonous, which could make eating the flowers a delicate business. More research, as they say, is needed.