Mid autumn is time to lift the tubers, as soon as the foliage has been blackened by frost. Clean of soil, cut back stems to about 15 cm and stand upside down for about 3 weeks in a frost-free place to drain water from them, trim off any fine roots and treat the tubers with fungicide.
Pack them in wooden boxes, in vermiculite, coir or similar medium. Store in a dry, cool, frost-proof place and inspect them regularly over the winter. If any mildew or rot has developed, cut it out with a clean, sharp knife and dust the cut surfaces with sulphur.