Oca/Corn/Huauzontle Polyculture — Still Seeking Low-Work Resilient Growing Systems.

In 2010 I posted here on interplanting Oca and sweetcorn. This year, I'm going a stage further by adding Huauzontle (or 'Aztec Broccoli') to that system. Huauzontle is a Chenopod crop producing greens and edible flower-shoots, historically an encouraged weed or tolerated volunteer in Central American maize fields.
Here are the three constituent crops ready to plant out on the 16th of June, Huauzontle on the left...

The Huauzontle seed came from Real Seeds, and was ridiculously fast to germinate; the seedlings were up in 48 hrs, so in future, I would direct sow with confidence. But this time they were multi-sown in cells a week or so after the corn.
The maize is Painted Mountain obtained in a seed swap parcel a few years back, (thank you Jayb). It gave 100% germination despite its age, in sowing conditions that were not really warm enough by normal standards. It's a many-coloured genetically diverse, heat and cold-resilient variety, bred to thrive in the Rocky Mountains. After last year's weather, I'm seeking resilient varieties! Two trays of commercial sweetcorn sown on the same day all rotted, thanks probably to chilly nights in the greenhouse. Not chilly by Rocky Mountain standards evidently.

The oca are a motly collection of leftovers stunted from being left in small cells too long.

Here's the scheme on planting day. That's a four foot wide bed...

 ...which has just been newly created by double digging, incorporating all available organic matter to full depth. Carrying through the resilience theme to the soil, there are even logs buried under there; anything to build up this silt soil, and give some water holding capacity.

Just four weeks after planting, quite remarkably the huauzontle was already providing greens and seed shoots for steaming, but proving too vigorous for this scheme, or at least is too thickly planted, and is shown here just before receiving a serious cutting back...

A few spare lettuce were squeezed along the edge too, and the paths mulched to limit water loss during the ensuing heatwave.

By the beginning of September the corn is ready to pick...

...and, despite occasional chopping back, the Huauzontle continued to be a bit too resilient. The Oca are definitely suffering from lack of light and water at this stage.

Here is the view of the bed on 31st October...

...The oca are expanding fast, fighting back, and flowering, with every indication of a decent harvest to be had by mid winter. The Huauzontle, disheveled by recent gale-force winds, has turned spectacularly red and carries a massive seed crop, so it seems likely that I, just like Central American peasants, will have it as a tolerated volunteer in seasons to come.
With wider spacing of the Huauzontle, this scheme would approach my ideal; no weeds had a chance, and the bed yielded well, but required almost no work input once created. And like the Forth railway bridge, it has redundancy — bits can fall off it, but it still works.

Oca True Seed Progress.

What little true seed that I managed to collect last autumn was sown in mid March, and here is the result so far...

...not a flush, but a long slow ongoing trickle of germinating seedlings. The difference this year, is that I surface sowed the seed, and it seems to have improved success, with the first emerging after four weeks, and no end in sight so far at ten weeks. They had artificial heat to start with, but for the last six weeks have been in an unheated greenhouse, with temperatures oscillating wildly from over 30°C to near freezing. Who am I to know, maybe this is helping.

Meanwhile, last year's true seed success story, IOW2, gets its first chance to grow from tubers. Here it is about to be planted out amongst the outdoor cordon tomatoes.

The soil is still very poor, but we'll see how they do.

Incidentally, I've settled on a quick and easy overwinter storage method for tubers; in autumn I just drop them into multicell trays, add dry compost on top, and leave them to it. It makes sense when there are lots of varieties to keep track of, since the cells can easily be labeled, and it's a simple matter to just start watering when shoots emerge, and they turn into plug plants...

Yacon — Storing and Dividing Propagation Caudices

Yacon propagules (or caudices) are easily bought these days, and most new yacon growers will quite rightly be expecting to save their own replanting material for future years. Certainly, that's what I confidently planned when I first grew the crop, but in fact I found out that it's quite easy to lose yacon caudices during winter if they are poorly stored.

The two killers are frost, and rot caused by cold wet conditions. Err, then there's desiccation if they dry out. Oh, and not forgetting mice.
So, simple enough you'd think, but finding a successful storage method has taken me a few years, and resulted in a few failures along the way.
I've tried storing them in plastic crates of damp compost in a greenhouse (one time frost got in, another year 'sweating' caused rotting).
I've tried storing them in cardboard boxes in an unheated room in the house (some dried out, while some sprouted far too early, and were then difficult to keep alive until planting out time)
Some growers claim success leaving them in the ground, but this can't be totally reliable, and would only work in favourable climates. The climate here is decidedly unfavourable.

In practice, the temperature criterium is fairly simple to control; I've settled on storing in an unheated brick-built shed (with the proviso that I may need to temporarily rescue them during times of penetrating frost).
Maintaining ideal moisture levels is not so easy, but my experiences have led to this method:-

When lifting crowns in autumn, I remove most of the spindle tubers for eating, but leave a few of the small ones attached. These (I assume) provide the crown with a reserve of moisture. Do not separate the caudices for storage — leave them attached to the crown, where they will be able to draw on moisture from the spindle tubers.
I brush off as much of the attached soil as is practical (if it is wet), and cut off the stumps of the stems as these often seem to be the starting point for rot during storage.
If the crowns have been lifted in wet conditions, I would leave them under cover for a day or two to dry off.
I then place the crowns in lidded buckets (the lids are perforated to avoid condensation) surrounded by a mixture of almost dry spent compost and very coarse sawdust. Any open and slightly damp medium will do, the important point is that it should not be too moist.
I then hang the buckets from rafters to exclude mice.

In March, I start checking the crowns every week, until I notice signs of growth...

This is a good time to divide the caudices and pot them up; small live buds confirm which caudices as viable. Any larger, and they will almost certainly be damaged during the violent dividing process.

I prepare by gently brushing away the storage medium to reveal the caudices, being careful not to harm any shoots ...

Then I start by trying to break the crown in half on any obvious line of weakness, though often a knife is needed for this first division. Thereafter it is usually possible to forcibly snap the caudices apart along their natural divisions. Be warned; this is not a job for a little old lady with arthritic fingers, or at least not unless she trains regularly by tearing telephone directories in half.

Each crown should provide between 5 and 15 propagules. Larger caudices can be further divided as long as each piece has at least one viable bud, but I prefer to leave them whole to make really strong plants.

Check each propagule for local rotting. Either discard, or trim back to healthy material for a fair chance of survival.
Pot immediately, and keep in a greenhouse, perhaps potting on again, before planting outside in May.

I've noticed that poorer, smaller plants, often provide more propagation material than larger ones. Based on that, and the fact that I got about 15 propagules from each of my plants, you should be able to work out how bad my crop was last year!