Back in November on my scavenger hunt to Taranaki, I found some oca (Oxalis tuberosa) tubers sprouting. I had never seen them growing before, didn’t know a thing about them other than how tasty the little blighters are, but jumped in anyway and bought a couple of punnets. I had a newly-developed bed and so popped them in there until I worked out what to do with them. It’s only taken about six weeks, but finally I’m catching up on just what makes a little oca grow.
I’ve always known oca as yams, and it does turn out that they are quite widely known as New Zealand yams. There’s always a been a bit of confusion around yams, sweet potatoes and if you add oca into the mix it all just gets crazy. I’ll leave The Phytophactor to sort out the other yammy issues. Our oca friends originated in the Peruvian highlands, didn’t have a lot of success in Europe but made their way to Aotearoa, probably at the turn of the 20th century and became a bit of a hit.
The plants are clover-like on top and the roots are like little fat fingers 40-200mm long. Reddish/pink is the usual colour, but they also come in yellow, white, or purple. They adapt well to poor growing conditions and do well in silty loams.
Growing oca in your garden in New Zealand
In New Zealand, oca are planted in November (so I was right on time). About February, when the foliage is about 30cm high, the oca are mounded up. In mid-March the yellow flowers appear and the tuber production begins. Frosts will cause the foliage to die down, just like potatoes. Digging begins in May and goes right through until September.
Eating oca – yammy goodness
When we were kids, Mum would roast oca just like potatoes and we loved them. She would also add them to our stir-fries. They can be sliced and grated into salads or coleslaws. I think they’re delicious and can’t wait to experiment with new recipes for my little earthen beauties.
Oca growing resources
Ian Pearson’s Growing Oca site
Photo by the lovely CalamitySue.