Aad: I potted the Gethyllis up in a pot with the bulb in a layer of pure sand and the roots extending down into a commercial potting mix. The first year it put up a small growth and then I placed it in a cool basement for the summer. With the advent of Fall I brought it up into the cool greenhouse and it started growth just on schedule. I've down this with most of the SA bulbs that had to be converted to Northern hemisphere growing conditions. I think the danger is to give too much water and have the bulb rot. Arnold On 11/13/12, Aad van Beek wrote: How long will it take to convert a bulb from southern to northern hemisphere and what is the best approach to do it. For instance is it beter to lengthen the dormant period or the active growth period