posted 1 week ago
I suspect mine are Dioscorea polystachia, obtained from a friend, who possibly got his from RealSeeds in Pembrokeshire, UK. A lot of their leaves are opposite, and the bulbils are tiny.
My tubers are planted individually in rose pots - tall plant pots. They're kept indoors in that state, I start watering in spring to encourage growth - but they'd probably start anyway. I'm aware slugs like them, so I'll only put them out when there's a good length on (raspberry canes are useful for climbing)).
Summer quarters are on an old dustbin of good compost. It's got a small hole 6 to 8 inches up - in a wet summer I've had the water table up to the surface without that. The yams send their roots down into the compost, no further than the water table (that'll be right at the bottom this dry year). Tops grow into a hazel, I introduce them to hanging twigs (less chance of snail attack).
In autumn I lift the pots and protect from frost. Then tip the bin and harvest the roots, dry them off and store in a plastic bag with my spuds. But first I check the pots - some will have given their all to the root in the bin, and there's no root in the pot. So I ensure there is a length of root in the pot for next year.
Hardiness: there was one year I was late harvesting, and freezing weather had arrived. Mush in the pots. Mush in the bin - until right at the bottom, some unfrosted root. In the ground the frost wouldn't have penetrated so deep, and I may have had a root breaking from deep. But, as others have said, extracting this root is no joke! Deep, brittle and thicker at the bottom. Someone cross it with carrot...