Last year I had two Yacon plants which produced some storage roots and a couple of large crowns covered in purple bumpy bits. These crowns have been stored in my garage over winter in breathable puts of damp compost. They’re now starting to show signs of sprouting with the purple lumpy bits producing whitish eyes.
The purple lumpy bits are the rhizomes for next years growth, each little white knobbly eye is capable of shooting and growing a new plant. Splitting it up into chunks with a few eyes on each takes a bit of brute force but once you’ve made a start it goes along swimmingly.
Researching on the web it seems that the size of the crown and amount of Rhizomes is inversly proportional to the size of the storage tuber harvest. As 2 crowns gave enough rhizomes to start 40 new plants you can see how small my last years harvest was.