By the way, this is part of the care sheet that was sent to me by the original owner:
In the fall with the risk of frost (eg if you are growing in zone 5) the pots are knocked over so they will not get any rain and the pot will dry. Alternatively, it could be placed in a greenhouse or a patio and allowed to dry. The leaf will die back. Do not cut it off until it completely yellows and collapses as it may be translocating sugars into the corm until it is withered. Once it is dry, it can be stored in the dry growing medium until spring and then dug up so that small corms can be seperated from the mother corm. Winter storage can also be in dry peat or in the open air. Storage temperatures should be somewhere between 42 and 50f. If stored too warm, the corm may grow at a time when you are not prepared to grow it. Corms can be started in pots indoors in cold climates and then transferred outside when night temperatures do not drop below 55f. Remember, the warmer the temperature the faster the growth and the longer the season for the leaf. This species is cold hardy and can survive in ground as far north as Raleigh, North Carolina if soil is well drained.
Propagation is generally by offset. When the corm is dug unpotted in its dormant state, you may find small corms attached by stolon-like structures to the main corm. These can be seperated and potted individually.