Tropaeolum notes
totototo@telus.net (Sat, 12 Jan 2008 12:55:53 PST)

On 11 Jan 08, at 15:56, Jane McGary wrote:

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