Widgets Blog - Emma the Gardener

The Great British Kitchen Garden Revival

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Kitchen garden
The kitchen garden at Hampton Court Palace contains some long-forgotten vegetables and herbs

The Great British Garden Revival has been gracing our screens again this year. In each episode two famous TV gardeners champion a particular plant or style of garden, which they think is in danger of being forgotten. This year that has included lilies and knot gardens, lavender and woodland gardens. The idea is to “attempt to inspire the nation to to save Britain’s rich gardening heritage”. There’s obviously an interest in our gardening history, as people have been talking about the wonderful Tudor gardens that appear in Wolf Hall.

There’s not much edible amongst that lot, but we have a great tradition of kitchen gardens in this country, and I thought it would be interesting to champion some of the ignored or forgotten plants that once graced our kitchen gardens and our tables, but have fallen from favour.

I wrote a section on forgotten vegetables for Jade Pearls and Alien Eyeballs, noting that Britain isn’t the only nation to have let some varieties slide:

“While it is easy to see how vegetables from other countries may never have found their way onto our plates, and why heritage varieties may have fallen from modern commercial favour, there are vegetables and fruits that were once common but are now largely forgotten. These aren’t wild plants, languishing by the roadside waiting for their virtues to be rediscovered, but cultivated ones that for some reason are no longer popular.

Given their long history of vegetable gardening (including their beautiful pótagers and the famously intensive market gardens of Paris in the 19th century), it is perhaps not surprising that the topic of forgotten vegetables seems to resonate most strongly in the French. It is often easier to find relevant information (although harder to read the results!) if you search for ‘les légumes retrouvés’ or ‘les légumes oubliés’.”

In the book I mention salsify and scorzonera, skirret, cardoons and tiger nuts, among others. That’s just a small selection of the goodies on offer if we pop into our time machines and go back to the gardens of history. For some plants, we wouldn’t even have to go that far back.

And so I thought this might prove to be an interesting blog meme – have you got a favourite ‘forgotten’ edible plant that you’d like to champion? If so, then blog about it and let me know the link and I will start a list here. You may even have an existing blog post you’d like me to point to. If you don’t have a blog, but would like to champion a species, then I’m happy to host a guest post from you.

If you’re not a blogger, but you can think of a plant in need of a boost then post it in the comments! We’ll see if we can find it a champion :)

Let the Great British Kitchen Garden Revival begin!

Posted in Blog on Jan 31, 2015 ·

Tags: carnival & unusual.

A garden of succulent edibles

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‘Egglings’, planted with succulents

Whilst I was munching my way through a particularly nice sandwich one lunch time, I began pondering the word succulent, and its various uses. In terms of food, succulent means tender and juicy. In my mind it has the same slightly indecent feel to it as moist, luscious, lush and pleasurable. But succulent food is definitely a good thing.

For a botanist, a succulent plant is one that has one of more fleshy parts that are used to store water in arid conditions. Sometimes the definition includes geophytes, whose storage organ is entirely underground, and sometimes it doesn’t.

And horticulturalists often make a distinction between succulents and cacti (for a botanist, cacti are succulents (but not all succulents are cacti)). For the sake of the following discussion, I’m going to stick to plants that are obviously succulent – those that have the characteristic swollen leaves and/ or stems.

Born and raised in a temperate climate (which is currently insisting on being very wet), I tend to think of succulent plants as unusual and ornamental. But, in fact, there are lots of edible succulents that we could include in our gardens. (And perhaps I should, since my inability to keep anything well watered is legendary!)

One that might be found in a British kitchen garden, if it’s a diverse one, is purslane. Portulaca oleracea is often considered to be more a herb than a vegetable, but it’s a very nutritious, annual succulent plant. Apparently it contains Omega-3 fatty acids, and you can enjoy its fleshy leaves raw or cooked. I think I’ve tried to grow it in the past; I don’t recall what happened to the plants – I don’t think any were ever eaten.

My little samphire plantation

Samphire (Salicornia europea) is a salt marsh succulent, which it is possible to grow at home. Victoriana Nursery Gardens sell samphire plants. I tried it once, and it’s fun because it has to be watered with salt water (so you have to be careful where you grow it, as salt water kills most things). I didn’t realise at the time that it was an annual, so I forgot to eat any before it died back. A happy plant should self-seed, so I will have to try that one again at some point. Rock samphire is a perennial, but possibly more difficult to cultivate. I have at least had the opportunity to try eating samphire. On my recent trip to Kew Gardens I selected a potato salad for lunch. It was made with roast potatoes, samphire and preserved lemons, and oh my gosh it was delicious. I’ll have to work out how to make that at home. First, preserve your lemons….

Another halophyte (salt-loving) succulent plant is Salsola, or agretti, Salsola soda. It can be grown from seed (which you can source from Seeds of Italy and Real Seeds); if I remember correctly then it has a short shelf-life and has to be sown the year you buy it. I had some last year – my notes tell me I sowed some in May 2013. Since it was rather a turbulent year, I don’t remember getting very far with it! I’ll add it to the list of ‘do overs’.

Succulents growing in the RISC Roof Garden

If I were to mention the topic of ‘edible succulents’ to a savvy gardener, I would expect them to bring up the houseleek (also known as Hens and Chicks, Sempervivum tectorum). I’ve never (knowingly) grown it, but it’s a good one for green roofs and gravel gardens, and a reasonably common garden plant. I don’t think I know anyone who tucks in, however. Have you tried it?

I once tried (and failed) to add the Hottentot fig (Carpobrotus edulis) to my greenhouse collection. It is a succulent grown for its fruit; amid dire warnings of its invasiveness (which is true, it’s a big problem on the south coast), mine simply failed to thrive.

And one I would like to grow (and once had seeds for, but they are long past their sow-by date) is the ice plant, Mesembryanthemum crystallinum, which is rumoured to be a nice, perennial, succulent salad plant. If you’re going to grow it then make sure you have the right ice plant – this is one of those times when the common name is applied to several different species, and if you’re going to put something in your mouth you need to know exactly what you’ve got!

The ice plant and the Hottentot fig are related – they’re both in the same plant family.

Dragon fruit
Dragon fruit cacti are easily grown from all those seeds…

I’ve grown one cactus for its edible fruit (my dragon fruit, a Hylocereus species), although it never produced any, and eventually succumbed to the winter weather when I couldn’t bring it indoors. I’d like to try and Optunia species, some of which are hardier. The prickly pear is O. ficus-indica, but the cactus pads are edible as well as the fruit. Some species are spinier than others, so the difficulty of harvesting your meal varies.

There are edible species amongst the Agave, including one famous for being made into tequila :) And Aloe vera has edible pulp, although I don’t know anyone who prepares their own from a houseplant. It’s a useful plant to have around, although according to Raw Edible Plants, the houseleek shares its skin-soothing properties, and is much easier to grow in a cool climate.

Then there’s the vanilla orchid, but it’s hard to grow a vanilla crop in cultivation because there’s a special technique for manual pollination you have to grasp (the job is done by an insect in its natural habitat). And Basella rubra or B. alba, Ceylon or Malabar spinach, which I keep meaning to grow. And Hibiscus sabdariffa (roselle, or sorrel) is on the list for next year already.

Have you got any edible succulents in your garden? I’m not sure a definitive list exists anywhere, but I thought it was an interesting topic.

Posted in Blog on Nov 29, 2014 ·

Tags: unusual & ethnobotany.

Trendy Pond

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Trendy Pond front
My new Trendy Pond, still in its packaging

The nice people at Swell UK have given me a trendy pond to play with – as you can see, I haven’t managed to take it out of the box yet, but might manage that this weekend. I’m hoping that it will make a nice water feature in the garden next year, and that I can plant it up with some edible plants.

Ryan has already said that he’s not keen on the idea of an indoor pond (one of the suggestions made on the packaging!), so we can safely assume that it’s going to live outside. It will hold up to 30 litres of water, and isn’t really suitable for fish, so I can just go nuts with the planting. The website gives the dimensions as approximately 45 cm wide by 30 cm high.

I was talking a couple of years ago (doesn’t time fly!) about wanting an edible water feature of some kind in the garden, and started a list of potential plants then. Of course, in the intervening time I had forgotten, and so started a new list when the pond arrived. The only plant I came up with this time that didn’t make it onto the last list was Water Pepper, Persicaria hydropiper.

I do have a book on Edible Water Gardens, which I never got around to reading when I bought it, so now that it is back from storage I can read that once I’ve finished Homegrown Tea. Given the small size of my new pond (which is purple, btw :) I’m leaning towards a bog garden rather than a full-on pond, but I might change my mind before spring. I’m also wondering whether I could combine two obsessions and have a pond filled with aquatic tea plants! But so far there’s only water mint on that list….

Have you got edible pond/bog plants in your garden?

Posted in Blog on Nov 20, 2014 ·

Last modified on Nov 20, 2014

Tags: gardens & unusual.

Unusual cucumbers

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Unusual cucumbers
Unusual cucumbers, grown at West Dean Gardens

It seems to be Cucurbitaceae week on the blog. Fresh from talking about Gynostemma pentaphyllum, today’s post is about some unusual, and ornamental, cucumber varieties.

Just before we moved house, Ryan and I had a much-needed weekend away on the south coast. We’d planned various visits, but whilst we were there I picked up a tourist information leaflet about West Dean Gardens. I’d heard of them, but hadn’t realised we were so close. Of course, we had to visit :) And after a wet day at Fishbourne Roman Palace and Gardens it was nice that the sun came out.

West Dean Gardens is a lovely place for a kitchen gardener to visit, and I’ll share some more photos in due course. There are lots of greenhouses, growing impressive crops of fruiting vegetables, and one of the things that caught my eye was a display of unusual cucumber varieties that had been grown in one.

Hedgehog gourd
Hedgehog gourd, Cucumis dipsaceus

Also known as the teasel gourd and Ekaleruk, you can buy seeds for the hedgehog gourd from Chiltern Seeds. They note that this plant comes from Arabia, and although it is usually grown as an ornamental, the fruit, seeds and leaves are all edible. They also say they have no recipes, but cannot recommend swallowing the fruits whole!

Cucumis africanus
Cucumis africanus

This one doesn’t seem to have a common name, and opinion is divided on whether or not it is edible. According to PlantzAfrica, the fruits “have been pickled and preserved at the Cape since the late 17th century”. However, there are other references to them being extremely bitter and inedible. It sounds like this plant may not be domesticated, and that variation in the wild population makes some fruits tasty and some not.

Cucumis zambianus
Cucumis zambianus

The common names for these cucumbers are confused – they could all be called a ‘horned melon’ or ‘hedgehog gourd’, and at some point they probably all have :) Horizon Herbs call this ‘kiwano’, but it’s not the kiwano I know and have grown, which is Cucumis metuliferus (I got my seeds from the HSL, but they’re quite widely available now). In fact, it seems that Cucumis zambianus is a relatively new species, first officially described in 2008.

South African Spiny Cucumber
South African Spiny Cucumber, Cucumis zeyheri

According to Trade Winds Fruit, these cucumbers are considered to be inedible, although it again notes that some plants will be more bitter than others.

Bur gherkin
Bur gherkin, Cucumis anguria var longipes

This last one is, perhaps, less ornamental than the rest. That might explain why the literature on Bur gherkin seems to be mainly scholarly ;)

I don’t think I’ve ever grown cucumbers – I don’t like eating them. However, Ryan does, so I may well try and grow Crystal Lemon next year. I have also failed to grow Mouse melons (Melothria scabra) before – they’re not a Cucumis species, but they are in the Cucurbitaceae.

What’s the most exciting cucumber you’ve ever grown? Do you fancy growing any of these unusual ones next year?

Posted in Blog on Nov 13, 2014 ·

Tags: unusual & fruit.

Photo blog: Hampton Court Palace

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Kitchen garden

The kitchen garden at Hampton Court Palace (which is in a part of the grounds that is free to visit, if you don’t want to see the Palace itself) is an impressive beast, growing some old-fashioned and unusual plants amongst the more familiar crops. These photos were taken on August 24th, which turned out to be a very hot and sunny day….

Tomato support
A novel way to support tomatoes

Good King Henry
Good King Henry, Chenopodium bonus-henricus

Salad burnett
Salad burnett, Sanguisorba minor

Costmary, Tanacetum balsamita, with a flowerpot label.

“Rampion, the Wonder Horse…” Couldn’t resist ;) Campanula rapunculus

Trick-madame, Sedum reflexum

Labelled ‘Hartshorn’, this is probably buckshorn plantain, Plantago coronopus

Scurvy grass
Scurvy grass, Cochlearia officinalis

Skirret 2
Skirret, Sium sisarum

Posted in Blog on Sep 30, 2014 ·

Tags: gardens & unusual.

The Jade Pearls and Alien Eyeballs Tour

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On the fence

It’s only a month until the publication of Jade Pearls and Alien Eyeballs, and in true plant hunter style I am donning my pith helmet and setting off on an adventure, exploring the digital world oin my virtual book tour.

I don’t have to go too far today, as I’m hosting a special edition of the Alternative Kitchen Garden Show, including a reading from the book. Here’s the tentative schedule for the rest of the tour, which will shape up as the month continues (shout if you’d like to fill an empty slot):

I’m also tweeting and updating the Jade Pearls and Alien Eyeballs Facebook page with related content.

You can preview the book over at Smashwords, and it’s available to pre-order on NOOK.

If you’re writing about the book, you can find cover images and photos of me that you can link to or download on the book homepage.

Posted in Blog on Apr 1, 2014 ·

Last modified on Aug 31, 2014

Tags: books & unusual.

March Berry-go-round: Unusual edible plants

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Welcome to the March edition of the Berry-go-round, a blog carnival devoted to all that’s wonderful and intriguing about Earth’s flora. This month I set a theme of “Unusual Edible Plants”, and bloggers from far and wide duly rose to the challenge.

Tamarisk Tree
Tamarisk Tree, by Robert Wallace, on Flickr

Gravity’s Rainbow took the opportunity to bring our attention to a post from the archives. Invasive species – making the best of a bad situation raises an important issue. What do we do about introduced species that turn out to be invasive in their new environment? Control of these species is often a costly, and largely impossible, task. Perhaps putting them to good use would be a better use of our resources?

Licorice seedlings, from tangent ramblings

The licorice seedlings Jeanette from tangent ramblings is growing with Aspirations of a licorice harvest are unlikely to cause any weed problems – the roots will be far too tasty to leave in the ground. And what is Jeanette planning on doing with the resulting bounty? Brewing licorice beer!

Quercus agrifolia
Coast Live Oak, by Eric Hunt, on Flickr

If brewing your own licorice beer from scratch sounds like hard work, then you’re going to be exhausted just reading about how to make acorn atole, over at In the Company of Plants and Rocks. The title spells it out: Acorn atole – not a convenience food. But acorn flour was a staple food of Native Americans in California, when they had no option but to grind, leech and bake their acorn harvest by hand. The result was a highly nutritious, and long-storing food. These days it’s only made for special occasions, even though modern technology makes the process much easier.

Ackee fruit by Loren Sztajer (CC BY-ND 2.0)

It’s the presence of tannins that makes the process of processing acorns so laborious. The ackee fruit brings food preparation to a whole new level – as Nature’s Poisons points out, ackee fruit are both deadly and delicious. A native of West Africa, ackee was brought to the Caribbean in the 18th century, and now forms one half of Jamaica’s famous ackee and saltfish dish.

Only the fleshy arilli are eaten, with the rest of the fruit discarded. Even then, you’re not entirely safe – the flesh is poisonous unless completely ripe, and the US bans importation of fresh ackee in the hope of avoiding poisoning cases.

Muskatnuss / nutmeg / noix de muscade /
Nutmeg, by Carmen Eisbär, on Flickr

You may be wondering why people go to such lengths to eat potentially poisonous foods, but in all likelihood you have one or two kicking around in your kitchen at home. Compound Interest has done a lovely article on the hallucinogen in your kitchen – the chemistry of nutmeg this month. Although nutmeg does get some attention as a possible “legal high”, ingesting more than a couple of muffin’s worth in one go is probably a bad idea, and Compound Interest tells us why.

Andean Roots, from Radix

As this month’s Berry-go-round has largely been a round-up of the time consuming and terrifying aspects of unusual plants, I’m going to end on a happier note :)

The wondrous Radix blog, home of the internet’s resident expert on all aspects of edible buried treasure, has recently celebrated its fifth birthday. As a special treat for us, Rhizowen wrote up a summary of everything his root crop research and ruminations have produced so far, in Radix: Alive at Five. Oca, mauka, ulluco and ahipa are just some of the unusual underground edibles he covers.

I hope you’ve enjoyed this month’s round-up of planty goodness. Keep an eye on the Berry-go-round blog to find out where we’re headed next month :)

Posted in Blog on Mar 31, 2014 ·

Tags: ethnobotany & unusual.

Carl Legge's Oca pizza recipe

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As promised, an exclusive new oca pizza recipe from Carl Legge. I also have instructions on how to grow oca, if you’re giving it a go this year.

oca tubers

Oca is a very tasty and useful vegetable tuber. It grows well for me in North Wales. It’s good ground cover and polycrops well with taller partners such as tomatoes. Fresh picked and raw, many varieties have a lemony (oxalic acid) taste which goes after exposure to the sun. The cooked taste is sweet. The texture ranges from that of a slightly less crunchy water chestnut to a soft puree which depends on the variety and how much you’ve cooked them.

Cooked they can be steamed, boiled, roasted, fried or sauteed. They can be used in sweet or savoury dishes and preserved or frozen.

When we first started to grow them in 2011, I tried to find traditional recipes for them, without much success. Lost Crops of the Incas says that: “In Mexico, oca is commonly sprinkled with salt, lemon, and hot pepper, and eaten raw.” The other recipes for them I could find were for roasted oca, or oca used in meat stews.

So I thought I’d have a go at producing a set of new recipes for oca in its new home. I’ve already written about Oca Homity Pie and Warm Oca Salad.

Here I give you oca used as a pizza topping. I think this is a first on the internet, although I’m very happy to be proved wrong.

This is delicious! The oca are sweet and they have a little bite still. I think the oca look like jewels: the colour variation with fresh coriander garnish certainly makes a visually striking pizza.

oca pizza

Oca Pizza Recipe

This makes one pizza of about 23cm (9 inches) circumference.

Pizza is best cooked in an oven as hot as you can get it, with the oven shelf in the top half. So preheat your oven to at least 230°C, higher if you can. I cook my pizzas on baking paper on a granite baking stone. If you’re not lucky enough to have a baking stone or a pizza stone, make the pizza up on oiled greaseproof paper or tinfoil and then place on a pre-heated oven tray to cook. This will give you a nice crisp bottom.

This pizza is great at room temperature too.


For the topping

350g of oca, cleaned and any damage cut away
Some pesto (any of basil, wild garlic, rocket will do) or parsley persillade or similar (there are recipes in The Permaculture Kitchen for these)
200g mozzarella
1-2tsp ground coriander (best if freshly done with coriander seed)
1/3-1/2 nutmeg, finely grated
Sea salt and freshly ground black pepper to taste
Extra virgin olilve oil
Fresh coriander to garnish

For the pizza

This quantity of dough makes enough for two 23cm (9 inch) pizzas. It’s not really worth doing any less. So make a second pizza with another topping, or cover and pop in the fridge to make a pizza or garlic bread the next day.

500g of strong white bread flour (or Typo ’00 flour)
5g (1tsp) fast action yeast
5g (tsp) finely ground sea salt
30g (1tbsp) extra virgin olive oil
350g warm water (it’s best to weigh for accuracy)


Make the pizza dough first.

Pop all the ingredients together in a bowl. You can use your hands, a food processor, or a stand mixer with dough hook. Mix the ingredients together until all the flour is wet and the ingredients are well incorporated. The dough will be sticky, don’t worry. The wetter dough helps you get a thinner base. Cover and leave in a warm place for 10 minutes.

Then do a quick knead of the dough like this. Bring the top (North) of the dough to the middle. Then do the same with East, South and West parts. Then do North-East, South-East, South-West and North-West. I call this a ‘Compass Knead’. Cover again and leave in a warm place for 10 minutes.

Then do another Compass Knead and leave, covered in a warm place for 10 minutes. Do one final Compass Knead and leave in a warm place for 30-50 minutes until the dough has risen by 50-100%.

The dough is now ready to use. You can keep it in the fridge, covered until you need to use it.

While the dough is proving you can prepare the oca.

Steam the oca for 5 minutes and allow to cool. If you don’t have a steamer improvise with a sieve or colander over a saucepan, or just put 5mm of boiling water into a pan and pop the oca in there, cook covered and then drain & cool. The vibrance of the colours fades a little, so don’t worry.

Cut the oca lengthways in half.

Now assemble the pizza (your oven is preheated isn’t it? And if you need a heated oven tray, you’ve got that in too?).

Get your oiled greaseproof paper or tinfoil ready. You may find that it’s easier to handle the dough if you oil your hands.

Divide the dough in two. Make one of the parts of the dough into a rough flat disc with your hands and pop the other in the fridge, covered.

pizza dough

Place the dough disc in the middle of your paper or tinfoil and then gently press and the dough into the shape you want. Coax it, you want to gently stretch it into shape and size, not tear it. You can make a little border round the edge to keep everything in place.

Then take your pesto or similar (I used wild garlic pesto) and spread it thinly over the pizza base, but not the edges.

Arrange your oca halves prettily over the base with the cut side down. Press the oca in slightly to fix.

Tear the mozzarella into small walnut sized pieces and arrange these between the oca, overlapping them slightly.

Sprinkle the ground coriander and grate the nutmeg over the oca and mozzarella. Season to taste with the salt and pepper. Drizzle a little extra virgin oilve oil over the pizza.

raw pizza

Pop the pizza onto your hot oven tray or baking stone and bake until the dough is brown and crisp and the mozzarella is nicely melted and has some colour.

oca pizza

Sprinkle over some fresh coriander leaves to garnish and lift the flavours and tuck in.

Simple and delicious, I hope you enjoy it.

There are recipes for delicious pizzas and much more in The Permaculture Kitchen.

Carl is launching his new book, The Permaculture Kitchen at the Edible Garden Show today, so if you’re going then make sure to seek him! If, like me, you can’t make it to the show this year then you can buy a signed copy direct from Carl, and there are details on his website.

Lost Crops of the Incas: Little-Known Plants of the Andes with Promise for Worldwide Cultivation
Ad Hoc Panel of the Advisory Committee on Technology Innovation, Board on Science and Technology for
International Development, National Research Council
ISBN: 0-309-54691-5, 428 pages, 6 × 9, (1989)

Posted in Blog on Mar 29, 2014 ·

Tags: food & unusual.

How to grow oca

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Oca seed tubers

For my Masters dissertation last year I did some research into gardeners who choose to grow unusual edible crops. I settled on two species to investigate, achocha and oca. In the past I’ve written about how to grow achocha – it’s a nice, easy plant and in a temperate climate you should have no problems getting a significant yield. You may have more of a problem dealing with the glut….

Oca (Oxalis tuberosa ) isn’t quite as simple. It’s increasingly easy to get hold of tubers in the UK, with them being marketed as very similar to potatoes – but without the risk of your plants being devastated by blight. But my research showed that many of the people who do try oca find their yields to be very disappointing. So how do you grow oca for the best results?

In its homeland, the Andes, oca is known only as a cultivated plant; it’s closest wild relative is still a bit of a mystery. There are lots of different varieties planted there; they come in different colours, and they’re used for different purposes*. Some have been bred to be eaten raw, some are best when cooked and still others are bitter and have to be processed into a dried starch product before they can be consumed. Some varieties are used more like a fruit than a vegetable. Oca is quite popular in New Zealand, where it’s known as the ‘New Zealand Yam’. Here in the UK you’re likely to have a choice of perhaps three or four varieties, sold by their colour. Who knows what they might have been used for traditionally? We’re not off to a flying start.

The problem is that oca is sensitive to day length. In the UK they only begin to produce tubers when the days begin to get shorter, and they’re frost sensitive. Selecting varieties that might crop here at all is a problem, although there are some amateur breeding efforts underway (and I’m looking at Radix when I say that) to develop a day neutral variety that will find life here easier.

Oca tubers chitting

So, given that this isn’t currently a plant that’s ideally suited to life in the UK, how do you get the best out of it? Essentially, oca is grown in the same way as potatoes. You can store tubers in breathable bags until it’s time to plant them out in spring, and if they start to sprout too soon you can leave them on the windowsill to chit in the light. When the risk of frost has passed, plant them out about 30 cm apart, under the soil like potatoes.

Since the tubers on oca form in a similar way to those on potatoes, it’s thought that earthing them up (piling extra soil on top of the plant once the foliage starts breaking through) will help to increase yields. However, you don’t have to worry about sunlight causing inedible green patches on oca tubers – they don’t have the toxins you’d find in green potatoes.

You can also eat oca leaves; they’ll have a similar flavour to sorrel, due to the presence of oxalic acid. Removing too many will affect your tuber yield; you might want to set aside some plants for leaf production and some for tuber production, if you want good harvests of both.

In the event of a heat wave, or a drought, you will find your oca suffer. They don’t like hot weather, and will sulk. Provide some shade, and plenty of water, to keep them happy. If blight strikes down your potatoes, the oca will be just fine. Traditional cultivation systems intercrop oca with other plants. Other tubers are a common choice, including mashua, ulluco and even potatoes. Sweetcorn is another option (and would provide some shade). In the Andes, oca is often grown with alliums to ward off pests, but they’re not bothered by much in the UK. Oca should thrive in a cottage garden style arrangement, mixed in with both ornamentals and herbs.

Research has shown that there’s a positive correlation between leaf size and tuber harvest, so it’s worth feeding your oca to promote leafy growth (or ensuring they are planted in hearty soil). Feeding will also affect their nutritional value, mainly their protein content. Oca tubers are known to contain twice as much vitamin C and calcium as potatoes, with a similar carbohydrate content. Oxalic acid levels are lower in the tubers than in the leaves, and the highest levels found in tubers are 7 times lower than the lowest levels found in spinach – so they won’t cause any problems at all in a varied diet.

Frosty oca

The difference between oca and potatoes becomes apparent at harvest time. Whereas you can dig some varieties of potato early in the season, and maincrops from late summer into early autumn, oca tubers don’t start to form until the nights get longer. And so you wait until the first frosts have killed off the foliage. And then you wait another couple of weeks, and then you dig up your harvest. If early frosts are forecast you can protect your plants with fleece. If you grow them in containers (and, like potatoes, they are reasonably happy in containers if well-fed) you can move them indoors.

Oca container

Eat the best tubers from your harvest and keep the smaller ones for replanting. Some of the varieties in the Andes are left out in the sun for a few days after harvesting to make them sweeter. Will that work in the UK? We don’t know – there’s rarely enough sun at that time of year, and we don’t know which varieties we have ;) You could try it. Oca can be used in all the same ways as potatoes, and also eaten raw. Their oxalic acid content gives them a slightly sharp flavour, often referred to as ‘lemony’. Carl Legge has developed an exclusive oca recipe for us, to promote his new book (The Permaculture Kitchen), and that’s coming up in the next few days, so keep your eyes peeled.

Oca flowers

Breeding efforts rely on the production of seed, not tubers. Oca isn’t known for flowering and setting seed easily – in fact, you will need two or more compatible varieties for pollination to take place. If you do get seed then collecting it can be tricky – the pods tend to shatter and scatter seed on the ground. However, seedlings will grow from self-sown seed, and can be transplanted. If you collect seed then germination takes around 19 days. You can also root stems in water as another means of propagation. If you develop a variety you like, you can of course then propagate it via tubers from year to year.

So… growing oca is exactly like growing potatoes. Except, it’s not really. But they’re pretty plants, with lovely tubers and who doesn’t like trying new things? If you need oca tubers, the two main suppliers in the UK are Real Seeds (with several different varieties) and T&M. You may also find them via smaller suppliers, local seed swaps or your internet gardening pals. And if you’re interested in unusual edibles in general, have a look at my forthcoming book, Jade Pearls and Alien Eyeballs, which will be right up your street.

If you’ve grown oca, and got a good crop, what’s your top tip for growing them?

*That’s also true of potatoes, by the way. The Andes are a very interesting place if you’re a fan of tubers and unusual root crops.

King, S. R. (1988). Economic botany of the Andean tuber crop complex Lepidium meyenii, Oxalis tuberosa, Tropaeolum tuberosum and Ullucus tuberosus (Doctoral dissertation, City University of New York).

Posted in Blog on Mar 25, 2014 ·

Tags: unusual & veg.

First day of spring

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Devil's claw

If you haven’t already seen it, check out Google’s doodle for today. To celebrate the spring equinox, the first day of spring in the northern hemisphere, they’ve got a little cartoon human watering the plants. They grow pretty fast – must be weeds ;)

It’s a work day, so I won’t be celebrating the first day of spring by doing any gardening, but I did get out to the allotment at the weekend to make some progress there. Ryan helped me to set up my water butt in a new (but still temporary) location. It doesn’t have a downpipe feeding into it as I don’t have a shed, but it will collect some water when it rains. Ryan also helped me to dig out some unwanted rootballs; I inherited a thriving population of thornless blackberries when I took on the plot, and if I don’t thin them down I won’t have any room to grow anything else!

I brought home some potting compost in which to sow some seeds – three varieties of sweet pepper (F1 Sunshine, Tequila Sunrise and Corno di Toro Rosso) plus Garnet, which is bred for drying and grinding into paprika. The white sprouting broccoli and flower sprouts I sowed on Sunday have already germinated and are pushing up little seedlings on my office windowsill (brassicas being the speed freaks of the seed world). Like the peppers, my final sowing will take a little longer. Ibicella lutea syn Proboscidea lutea is a variety of Devil’s Claw or martynia. These plants grow hard, spiny seed pods that are shaped like caltrops and stick into the feet of animals. It’s their means of seed dispersal. That would be enough to make them interesting, but those same seed pods are edible when immature, and can be turned into pickles.

I don’t know of anyone who has tried growing Devil’s Claws, so if you have then do let me know in the comments. You can read more about my adventures in growing unusual edible plants (and the characters I’ve met along the way) in my new ebook, Jade Pearls and Alien Eyeballs. The official release date is 1st May 2014 and you can preview the book at Smashwords. It’s also now available for pre-order from the NOOK book store!

Posted in Blog on Mar 20, 2014 ·

Last modified on Mar 20, 2014

Tags: allotment & unusual.

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