Wednesday, 11 May 2011

'Minor' Root Crops as Ground-Cover in Polycultures

Oca can provide extremely effective ground-cover within a vegetable polyculture, as demonstrated with tomatoes, or sweetcorn. But how about using other minor root crops in the same role?
Ulluco  for example...
Sprouting Ulluco tubers lifted from storage in sand, 15th March.

... and Chinese artichoke (below) both give cover earlier in the growing season, lasting through to the first frost. And being very definitely 'minor' in productivity, I can't justify either of them as a monocrop; my basic criterion is that bed-space must produce a decent kitchenable yield, preferably with the minimum of labour.
Chinese artichoke tubers

But even if they don't produce much crop, at least they can reduce my weeding and watering by acting as a living mulch around other more productive crops .
I'm going to give them both a try growing with climbing French beans, plus garlic and elephant garlic.

Last autumn the bean-bed-to-be was cleared too late to establish an overwintering green-manure crop, so without digging, I planted it with garlic and elephant garlic, then added autumn leaves, retained with steel mesh. Here's the scene in late winter...

In early April the mesh is removed, and the ulluco and Chi-chokes (previously started in pots in an unheated greenhouse) are added between the garlic. Plastic sheet is placed down the centre of the bed to warm the soil for the beans.
Pot-grown Chinese artichokes planted out, 3rd April
Initially, there's a lot of slug-damage to the ulluco, especially those with green stems. The red colouration of some varieties seems to offer protection against pest damage.

Slug-damaged ulluco, 15th April
Removing the plastic sheet, allowing access to foraging birds, seems to improve matters.

Bellow, supports added in readiness for the French beans. The weather is hot and dry, so the mulch is topped up with a layer of grass cuttings.
5th of May, (below) the French beans, started previously indoors in root-trainers, are planted out.

French beans added, 5th May
Just after the photo was taken I pinched out the tips of the Chinese artichokes to encourage more side growth. There's no sign of any weeds getting through the autumn leaves yet (apart from the odd oca volunteer - which will be tolerated for now).

All done! If the ground-cover crops expand to give full cover before the leaf mulch breaks down, then there should be no more work involved apart from harvesting. My one concern is that there may be excessive competition for moisture between the crops if there is a dry summer, but we shall see.

Update 9th June. First produce from the system is garlic...
... no complaints there.

Meanwhile, the beans are twining, and the ground cover is closing up well...
The Chi-chokes have just about reached full cover, but the Ulluco are slightly slower.

Update 30th June.  Next — the elephant garlic has died back, so harvest time:
Some have only formed rounds rather than cloves, probably as they were slightly late getting planted. Lifting them caused a bit of disturbance to the Chi-chokes' roots, but hopefully no serious harm done.

Update 3rd August. The beans have been cropping well for about four weeks. The ground cover is complete, and virtually no weeds have made it through.

Update 22nd November. The beans and their supports have been removed. The first picking of tubers, a square foot of the bed, delivers enough Chinese Artichokes for a meal...
 I feel a stir fry coming on.

Update 16th January. I'm continuing to lift tubers as they are needed in the kitchen. As you can see there are plenty of volunteer Oca to be had amongst the Chinese artichokes...

The Ulluco have now been killed by frost, so I'm also lifting them now. They've done better than last year, but that's not saying much.



  1. I'm growing Chinese artichokes for the first time this year, and they're in tubs... but I will be watching your results with interest :)

  2. Hi Emma, at least you will not have unwelcome volunteers in your beds next season.

  3. Where did you find ulluco? I can't find it anywhere

  4. Hi Dozito. Often they can be had on Ebay ay this time of year. Otherwise it's down to internet swaps. Good luck with the quest.

  5. www.vreeken,nl