I planted two varieties of this obscure South American root crop last spring; one white and the other red. They went in a foot apart, in rows two feet apart. It didn't do much till around midsummer, when it started spreading out. It's frost-sensitive, and the tubers don't form till the top growth is dying back. I fleeced it, and meant to harvest it for Christmas. Thanks to the weather and a bad fall, I only got it up a couple of weeks ago.
Yield was very variable, from a pound or so to nothing. I'm not sure why, but some of the tubers I put in were very small. The red hadn't suffered from the frost at all, while white tubers on the surface had gone soggy. There was very little slug damage, and I found none underground. They taste lemony; allegedly they turn sweet if they're left in the sun, but I didn't try this. I'll be planting again shortly. This time I'll use larger tubers, and hopefully I'll do better.