Last winter, I came home from the local ’seedy Saturday’ with a bag of interesting plants to try, including three oca tubers (I’ve since discovered there is a huge variety of oca types, but I didn’t get any information about what type my tubers are). Oca, or Oxalis tuberosa, is a food plant I’ve read about, but never encountered before and I’m generally game to try new plants, even if I have no idea if I’ll like their flavour.
Along with potatoes, a handful of other tubers were, and I assume still are, grown in the Andes – including ulluco, anu (also called mashua) and oca. All four were grown together in the same field (I’m keeping my eyes open for ulluco and anu so I can try them as well), perhaps taking advantage of different subsets of nutrients. I can see an huge advantage to not relying on a single crop as your staple, a variety of tubers makes sense. The growing advice I found said to plant oca in the spring, then wait until after there has been a few frosts to harvest because the plant doesn’t start producing tubers until days get shorter. Potatoes was once like this as well, so if you were growing potatoes in the sixteenth century you would have gotten the same advice.
I planted mine directly in the ground late spring. My triad of oca tubers were quick to produce beefy three part leaves, and by late summer there was a nice mound of well behaved foliage – which was good because I had planted other plants a short distance away (potatoes on one side and anise on the other). By September, the oca began to flop over, sprawling into the other plant’s space after I’d already harvested them. Late October, I peeked under the ground and could confirm tubers were forming.
We’ve had a couple of frosts here so I bit the bullet and dug up my oca last weekend. From the three tubers I started with, I got roughly 1.2 kg which seems pretty good for my first attempt at growing this plant. I’ve read to expect 0.5 kg per plant, so there is an opportunity for me to do better next year. Wikipedia claims oca has 255 calories per 100 g (or 0.26 calories per gram), which means my harvest works out to a grand total of 312 calories – not enough to keep a person going for long, but a start. Something nibbled on some of my tubers, I’m not sure what but I was very careful to only select non-nibbled tubers to plant again next year.
And finally, we got to eat some. We tried a few slices raw. I’ve read some varieties contain a lot of oxalic acid which gives a lemony flavour, but not my variety. They had the texture of a water chestnut, which gave a nice crunch, but not much flavour. I don’t think I’ll bother with them raw. I fried some up like potatoes and they tasted kinda like potatoes, that is, somewhat bland in a staple food kind of way. Oca will be perfectly acceptable to me treated like a potato, my tubers for next year are already safely packed away.
As an after thought, I see that Emma over at the Unconventional Gardener hasn’t harvested her oca yet – she’s in a similar biome to mine, so perhaps should have left mine in the ground a little longer.