It’s December which means it’s harvesting time for oca tubers. Oca tubers are also known as New Zealand yam and oca tuberosa. At the moment it is still not available to buy in supermarkets in the UK. However, the tubers are sold on ebay for planting between September and December. It is price according to the size of tubers. At the moment they don’t cheap as potatoes or Jerusalem artichokes. It is available to buy at around end of November to February. Tomato harvest today
Encourage more tubers to form
They are easy to grow and don’t need much care. All they need is a sunny spot, some space and well drain soil. The tubers don’t form till there is less than 12 hours of daylight hours. So come autumn they will start forming, if one gets frost early do give them some protection so that the tubers can form. Lightly bury the foliage stems onto some compost so as to encourage tubers to form come autumn time. One will see tubers forming on these buried stems. When the frost arrives the folliage will die back. The oca tubers are ready to harvest. Gently lift them up from the soil.
Oca tubers do contain oxalic acid they will have lemony acidic taste to them when they are freshly harvest. It’s the same taste as rhubarb and sorrel leaves as they contain oxalic acid. Leave them expose to sunlight the flavours will be come sweeter and more enhance.
For fabric dyeing the leaves of oca tubers can be use as natural mordant due to the oxalic acid content. However it is not use very often as it is not easy to get hold of oca tubers.
Leave some behind for next years crop. They will need protection from frost and dampness. Store them with some vermiculite mixed with soil as they will rot from dampness. I use to store them in a cold spare room. This year I plan to store them in my greenhouse or shed.
Oca tubers are good to use like potatoes but with a flavour of green apples.