On 11 Jan 08, at 15:56, Jane McGary wrote: > I wonder if anyone has successfully propagated these plants by cutting > the tuber (which looks like a little potato). Many, many years ago at a one of the study weekends, Paul Christian held forth on the propagation of bulbs. (Memory says it was a Hardy Plant Study Weekend at Edmonds, Washington sometime in the mid or late 1980s, but don't quote me.) One of the most interesting sub-topics was vegetative propagation of cyclamen; perhaps the same method would work for tuberous tropaeolums. The technique called for cutting out the growing point from the cyclamen tuber (something like removing an eye from a potato you are going to eat for dinner), washing the wound with alcohol to remove the slime exuded by the tuber, packing the wound with sulfur, and replanting the tuber. He added that the growing point itself could be de-slimed with alcohol and sulfur and itself replanted, though there was no guarantee it would survive. After removal of the growing point, dormant buds on the surface of the tuber would then sprout, allowing the tuber to then be divided once these were well established. I do not know what success rate, if any, was claimed for this technique, but one can only suppose that it was good enough to warrant risking the loss of an uncommon form. An analogous propagation trick for crocus forms that do not multiply vegetatively was to pluck the growing point out of a corm when it had started to elongate. As with the cyclamen trick, this caused dormant buds on the surface of the corm to grow, each one forming a new corm in due course. As for sulfur, I remember Paul Christian's comment that it was a very good fungicide and stayed where you put it. To this day I dust cut surfaces with it when dividing certain plants, e.g. Eranthis tubers. I don't recall what time of year was recommended for these treatments but suppose for crocuses it would have been in late summer when they begin to stir back into life after summer dormancy. Diane Whitehead was very likely at the same presentation and may be able to comment. -- Rodger Whitlock Victoria, British Columbia, Canada Maritime Zone 8, a cool Mediterranean climate on beautiful Vancouver Island