Monday, 6 December 2010

Propagating Oca from Slips & Cuttings

Back in September I was lucky enough to receive a black Oca tuber brought from Lima. It was determined to sprout, having just been whisked away from Peruvian springtime, and despite being stashed in dry sand at low temperature to try to hold it through the winter, the tuber took a while to get the idea, and in the mean time produced several long shoots. Although unintended, once the situation arose, the propagation opportunity was just too good to miss.

'Slips' can be taken in a similar way as with sweet potatoes.
Roots start to develop from the Oca tuber itself, but what makes this method so easy is that roots also tend to form spontaneously at the base of the shoots if they are in contact with soil. It's a simple matter to gently break away the shoot, roots and all, and install it in some sandy compost.

Add gentle warmth, and after a couple of weeks the plants are growing away.

It's an easy way to multiply up a particular cultivar before the start of the growing season.
Placing the tuber in just-damp sand with some warmth during late winter should encourage the rooted shoots to appear.

Incidentally, cuttings taken from growing stems are also very easy and reliable. A large cutting taken as late as September will even be able to form a few small tubers before the frost arrives.
To give an idea of Oca's vegetative powers, I've seen diseased stems that have been completely rotted through near their base (photo here), collapse on to the soil, put down new roots and recover unaided to form a new plant. So no need for hormone rooting compound here!


  1. I enjoy reading your blog. I have had a reasonable crop here in Ashford, Kent. They were knocked down a bit by an early frost in October but they were partially covered by fleece so didn't succumb completely. I have just harvested them after the snow thawed. They seem undamaged by frost except for the odd one that was on the surface. I was curious as to the best way to store them for the winter but this post answers that - in sand. Are there any other ways? Perhaps a post on winter storage? I'm very keen to see how you get on with the black one. Shaun, Kent.

  2. Hi Shaun, well done for timely fleecing, and getting the harvest in. It has not been an oca year.
    Oca tubers are actually quite unfussy about storage conditions. I usually just put them in egg boxes in an unheated room. They dry out a bit over winter, going slightly wrinkly, but they re-sprout in spring without any problem. Keeping them in dry sand or spent compost/composted bark chips or whatever, keeps them looking better, as it slows the drying process.
    Certainly, avoid storing in poly bags, as you are likely to get some rotters (especially if any slightly frost-damaged tubers have sneaked past inspection).

  3. Good to hear about how to store them in sand - I wasn't sure what to do, so I just put them in paper bags in a refrigerator, but I think that might dehydrate them if I leave them in there too long.

    Really interesting to hear about how well oca can be easily propagated using slips. I observed oca's rooting ability this year when a large shoot broke off from one of my oca plants. I put it in water for about two months to see what would happen and it rooted. I planted it in the ground once it seemed to have enough roots and managed to get several small tubers off of it.


  4. that's a good idea. It came to my mind this autumn when I collected the very few of what I planted.

  5. I stored mine in a cool staircase in used dry potting mix in shallow boxes. They did not dry out even a tiny bit. They started to sprout a week ago so I dug them out and put them on the surface of the soil. They will stay there until planting time in April (I will pot them up fiirst before they go ut into the garden soil)