I have an Oxalis Triangularis. It's winter here and the plant is in dormancy (Not growing, faded colour, looking sloppy). I know that you can get corms from the plant (This is how I started). I do not know when these corms are "ripe for the picking". When is the best time to dig them up? And how long can the corms last without drying up or rotting once I dig them up? You think it would last half a year?