So far, we have hardened off plants for two weeks, then planted them out in the field slightly deeper than they were in the pots. This has generally worked well for oca from tubers and cuttings. It appeared to work well for the seedlings at first. Then the wind arrived.
We live on the coast, where our dominant spring/summer weather pattern is created by inland warming. As inland air rises, cool winds flow inland off the Pacific. That means that any time the weather is clear inland, we have winds that start in mid-morning and last until evening. They are not particularly strong, but may blow at 15-20MPH all day long.
Oca is generally pretty resistant to wind, although it sometimes causes us problems with flowers and seed pods dropping. So, I wasn't too worried when we got a week of such winds after planting out the first bed of oca seedlings. That was a mistake.
Oca seedlings have much less tolerance to wind than tuber-grown plants or even minimally rooted cuttings. Two days of steady wind badly damaged about 400 seedlings, to the point that I am not sure that more than a small percentage of them will survive. That is certainly a disappointment, although the sting is relieved somewhat by remaining seedlings that had not been planted out and the promise of more seed this year.
The question is: what should I try next? I could harden the seedlings off for a longer period, although moving a thousand plants in trays in and out of shelter every day for weeks may not be possible. I'm considering two possibilities and may try both.
The first option is to wait and start seeds outdoors. We get volunteer seedlings here, so I know it is possible. They are very slow growing compared to plants started indoors, but they also are able to withstand the rigors of the environment. So, perhaps starting batches of seed outdoors in April may provide hardy, transplant-ready plants by July or August. There is definitely an appeal to the labor savings.
The second option is to grow the seedling generation entirely indoors. Even a plant only four inches tall is capable of making mini-tubers. I could start plants indoors and put them in total darkness once they reach a certain size. The mini-tubers could then be planted out to the field with the greater hardiness of tuber-grown plants. The additional advantage is that multiple tubers will often be produced, which provides some backup. I think four months should be sufficient to produce mini-tubers.
Of course, neither option solves the immediate problem, which is the remaining seedlings that I have to plant out this year. As I am limited by time (although our success with the store has raised the possibility of doing this full time eventually, it remains a hobby for now) I'm just going to have to harden them off a little more and keep planting them out. Some will survive, but more will not. I think that I will try planting them deeper and at an angle in order to put more of the stem underground. This will reduce wind exposure and provide more opportunities for the plants to resprout if the topgrowth is damaged.
On the up side, this year will definitely select for hardier varieties. Even if only a tenth of the plants survive, that is a lot of new oca to evaluate and the education that I've received in raising so many plants to this point will certainly pay off in future years.
Hopefully some of you who are growing from seed this year will read this before you repeat my mistake. I would be interested to hear what you try and how it works for you.