On Oca

[British Red]

This year we decided to grow Oca...

Oxalis tuberosa (Oxalidaceae) is a perennial herbaceous plant that overwinters as underground stem tubers. These tubers are known as oca, from the Quechua words okka, oqa, and uqa; New Zealand yam; and a number of other alternative names. The plant was brought into cultivation in the central and southern Andes for its tubers, which are used as a root vegetable. The plant is not known in the wild, but populations of wild Oxalis species that bear smaller tubers are known from four areas of the central Andean region.Oca was introduced to Europe in 1830 as a competitor to the potato and to New Zealand as early as 1860. In New Zealand, oca has become a popular table vegetable and is simply called yam.

..why? Well apparently it crops like potatoes and is described as

Oca is grown and used just like new potatoes, although they are smaller than potatoes. It has a lemony taste and is very easy to grow as long as you have a moderately long season. It is completely unrelated to potatoes and so of course not affected by blight.

One of the 'Lost Crops' of the Incas, this is one of the staples of people in Bolivia & Peru. A very easy crop to grow, with a taste just like potatoes with lemon sauce. No need to peel, just boil and serve with butter. Mmmmm.
And the lush green foliage with yellow flowers is actually rather pretty in its own right. Very few pests seem to like it, so its a real 'no work' crop.

Almost too good to be true isn't it? Yep! Its a good crop. But that crop that has no pests, needs no work and crops reliably and heavily is guarded by dragons and unicorns and the seed is only available by passining into Narnia!

So in March we ordered some tubers in red....


Red oca by British Red, on Flickr

and Orange


Orange Oca by British Red, on Flickr

These were chitted (sprouted) in seed trays in a cool dark shed and planted a foot apart when the risk of frost was past.


Planted oca by British Red, on Flickr

Three weeks later, the first growth showed


Oca first growth by British Red, on Flickr

a couple of weeks after that, leaves appeared...sort of clover / wood sorrel in appearance


Oca 22-4 by British Red, on Flickr

A month later....not much bigger!


Oca 25-05 by British Red, on Flickr

About June they got going


Oca PLants by British Red, on Flickr

And just kept growing - but never got above a foot tall...just bushier.


Oca November by British Red, on Flickr

The plant needs to be frost killed before harvesting as it pulls its growth back into the tubers. Our first hard frost was the last day of November. The plants need to be left for a fortnight after this.

Two weeks later - this was how they looked


Frosted Oca by British Red, on Flickr

The tubers are quite shallow and in soft, unfrozen soil can be lifted by hand. The tubers are quite prolific


Oca Tubers by British Red, on Flickr


Lifted Oca by British Red, on Flickr

We washed the tubers and they cleaned up nicely.


Washed Oca by British Red, on Flickr

Although not subject to blight, we noticed they are subject to wire worm - and those growing on the surface showed sign of a few being gnawed (rabbits or rats we suspect). These were discarded.

We tried the Oca boiled


Oca in Saucepan by British Red, on Flickr

It was interesting to note the colour faded in boiling


Boiled Oca by British Red, on Flickr

Taste - like a boiled fresh new potato. Not much of the claimed lemon taste - but...something....nice though

We also roasted some of the boiled tubers


Oca in Esse by British Red, on Flickr


Roast Oca by British Red, on Flickr

Ended up like a soft roast new potato - I would only blanche them prior to roasting next time.

So...what do we think?

Well the best and largest of the tubers have been cleaned


Seed Oca by British Red, on Flickr

and packed in dry straw ready for planting a large bed in the Spring


Seed Oca by British Red, on Flickr

Red

 

[Outdoordude]

Nice one BR. Never heard of them before. So are they to good to be true or not?

 

[Mesquite]

Looks really interesting Hugh

Though I have to confess when I saw a picture of them all cleaned up my first thought was witchetty grubs

 

[British Red]

Nice one BR. Never heard of them before. So are they to good to be true or not?

Lower yield than spuds but blight resistant. Not resistant to all pests. Useful in that they crop later than most stuff except brassicas and parsnips....

Useful....but no miracle crop

 

[johnnytheboy]

So what tasted the best, red or orange? It looks like a great project!!

Would you recomend this as my first project in my new raised box?

 

[British Red]

Not much difference in the colours tbh!

They are spendy to buy....but after that, they are self sustaining - just keep a few from the first crop. Nice to eat, fairly wind resistant.

I plan to undersow them with field beans next year - and get two crops from the same space.

 

[Toddy]

Thank you for the post; very interesting

What kind of multiplying of the tubers, weight wise, did you get ?

cheers,
M

 

[British Red]

Weight and number wise I'd say 20:1....you do get smaller ones but none get really large unlike spuds.

 

[johnnytheboy]

So whats undersowing then, sorry novice here!

 

[British Red]

Err - imagine growing a low growing crop....like...bush peas and a tall crop....like runner beans.....in the same ground at the same time. In nature tall growing plants are interspersed with low growing plants - brambles under trees - same principle. Two crops in the same space. If you undersow with something bushy, you don't need to weed.

 

[slowworm]

I've grown them for several years now and find them trouble free, a little slug damage this year but it's been a very wet and sluggy year. We like to eat them in stir-fries, where they stay a bit crunchy like lemony water chestnuts, or in soups. The leaves are edible but check the warnings (oxalic acid) here: http://www.pfaf.org/user/Plant.aspx?LatinName=Oxalis+tuberosa

Red, did yours flower this year? In a good summer they are quite ornamental with loads of little yellow flowers.

 

[British Red]

They did mate ...but not in a prolific way....just a smattering. The foliage is attractive in itself though...could easly be grown in an ornamental bed as ground cover

 

[Bushwhacker]

Loving this. Three weeks in a row that I've learnt something new and interesting.

 

[British Red]

Glad you liked it buddy. Today will me more prosaic...making cranberry sauce with home made port and gingerbread men with my daughter.

FUN!

 

[Goatboy]

Hi Red,

Must say your post piqued my interest and I went looking, found the Reel Seed Company http://www.realseeds.co.uk/index.html and they have some nice plants and seem pretty ethical. You used them before? The oca look good and I fancey giving them a try. I think I've seen them in Wholefoods Supermarket in Glasgow, will give them a taste if they do.

Cheers for the post,
Goatboy.

 

[Hog On Ice]

Err - imagine growing a low growing crop....like...bush peas and a tall crop....like runner beans.....in the same ground at the same time. In nature tall growing plants are interspersed with low growing plants - brambles under trees - same principle. Two crops in the same space. If you undersow with something bushy, you don't need to weed.

do you think oca with Jerusalem artichokes would work OK? In other words two tuber type plants possibly harvested at the same time?

 

[British Red]

Goatboy, realseeds are an excellent firm - thoroughly ethical and indeed will give you instructions on how to save your seed so you don't need to buy from them again! Thoroughly recommended by me.

HOI, thats an ingteresting thought. I think the JA would die off first and you might have to remove the top growth - but I see no reason why the tubers couldn't be harvested together. Should make a sustainable food patch too....no need to re-seed!

 

[Elen Sentier]

do you think oca with Jerusalem artichokes would work OK? In other words two tuber type plants possibly harvested at the same time?

Ummm! In my experience, wherever you plant jerusalem artichokes you will have them forever! Fab hedge-plant, grows in hedge bottoms and will make a good screen if you like it or need it, but if you want to use the bed again for something else don't put JAs in it!

 

[robin wood]

Oca look great....beware the fartichokes.

 

[HillBill]

The american indians had a 3 crop system

They would plant corn, beans and squash in the same ground The corn would go in first, the beans would then grow up the corn with the squash growing on the ground below / between them.

Its just a high efficiency/max production system for a given space.

So whats undersowing then, sorry novice here!