Question on propagating a difficult African violet:

I have been growing and propagating african violets successfully for many
years. Usually I propagate by putting leaves in vermiculite, but
occasionally in water or potting soil.

I have one plant (my only one with red and white blossoms) that has defied
all my attempts to propagate it. In water, in vermiculite, in potting soil
-- the leaf just rots. Once in a while I get some roots in water, but when
I plant it it rots.

Any suggestions for something new to try? Or is this plant at a genetic
dead end (at least at my house). It's getting old, and I don't want to
lose a chance to have more of those beautiful blossoms.

Answer:

One possible reason could be that the actual plant itself is not really
thriving at the moment. If the leaf you try to grow from isn't healthy
sometimes it will just fail to root, but instead continue to deteriorate as
it would have on the mother plant.

Another problem could be that the conditions are just not right for
propagation. I don't know where you live, but if temperatures or humidity
are too low, that could make it hard for the leaf to root. Really
excessively high temperatures with excessive moisture gives fungus problems
that lead to rot the conditions in which they thrive.

I make the following suggestions:

1. Make sure that you take the healthiest leaf you can from which to
propagate - young enough to have sufficient vitality. Vermiculite is an
excellent propagation material as you have obviously found before. In this
case, however, it might be preferable to mix equal parts of perlite with it
to make sure the leaf isn't staying too wet.

2.  Sometimes leaves that are reluctant to propagate will do so if they are
grown in terrarium conditions. Some kind of transparent cover with some
(restricted) ventilation is indicated, but not if you have temperatures
above 30 degrees C. with humidity up around the 80%, this being a bit like
the interior of a terrarium anyway.

3. If the mother plant is really thriving and you feel very courageous, you
could cut the top out of it (hoping to root that) and see whether it
produces a number of sideshoots (suckers) that you could grow on as new
plants. Of course in the unlikely that the main crown and the sideshoots
fail to root you will have lost the plant, but it is most likely that they
will all grow.

4. A slightly more difficult manner of propagation is from the flower stems.
Remove all buds and flowers from the stems and reduce it to one or two
centimetres long only. Keep the two tiny leaves that are formed at the base
of the flower spray. Plant with these leaves at the potting mix surface.
Success rates can be low but you will not have damaged the mother plant by
taking the flowers.


Chapter 11 of "African Violets for Everyone" has a full treatment of the subject of propagation of African violets.