Propagation Of African Violet

There is no doubt that it is easy to propagate
African violets, especially as there are several methods to increase
successfully the number of plants from one. These methods are from a leaf, by a sucker or offset, by division and by seed.

Propagating from a leaf

All but one type of African violet propagate easily from leaves, although
for greatest success the correct leaf must be selected. Thus the leaf must be
mature and still have a good deal of potential growth in it; it is a mistake
to take an old, nearly spent leaf from the outermost layer of leaves,
because although it will produce plantlets it will take a long time to do so
and they will not grow into such good mature plants. Nor should a young
leaf from the centre of the crown be taken, as leaves do not achieve their
full potential for propagation until they have grown to full size. Also its
removal from the crown will spoil the shape of the plant. For rosette
types, a leaf from the second or third layer of leaves from the outside
would be the most appropriate. With trailing hybrids, a leaf from a similar
layer on one of the branches should be removed for propagation.

The leaf is taken cleanly from the main stem of a rosette or the branch
stem of a trailer by a sharp sideways tug so that no stub remains, as this
could rot and infect the main stem. If a stub is left it should be removed as
closely as possible to the stem. The leaf petiole should be trimmed to a
length of 1.5in (4cm) and cleanly cut at a slanting angle using a sharp bladed knife or razor blade. The slanting cut is to expose a large area of
tissue from which roots and plantlets will grow.

Sometimes one is given a leaf of a choice or rare hybrid, and its petiole
is accidentally broken off at the base of the leaf blade. All is not lost,
however, because a short stalk can be made by cutting away a small
section of the leaf blade on either side of the main vein. This cut leaf may
then be propagated following the normal method.

When propagating variegated hybrids, the leaf taken should have as
much green color in it as possible. Even an all-green leaf from a variegate
will produce variegated plantlets.

Rooting in compost
A leaf from a standard or large-sized plant should be potted one to a 2in
(5cm) pot so that the minimum amount of moist compost may be used.
With smaller sized plants it is best to pot two leaves back-to-back in a 2in
(5cm) pot. The reason for this is so that roots can quickly fill the pot, thus
allowing the plantlets to grow quickly. The pot should then be labeled
with the name of the hybrid and the date of potting.
Some hybrids have very large leaves, and these would easily fall over if
potted into small pots. These large leaves may be potted into a polystyrene
cup that has had one side cut away to half its depth so that the leaf blade
may be supported at its back by the remaining rim of the cup. It is unnecessary to use hormone rooting powder, as African violet
leaves root quickly providing the correct one has been taken. The potted
leaf should be put into a covered propagator or enclosed in a polythene bag,
and placed in a warm, brightly lit position out of direct sunlight. If
condensation builds up on the inside of the polythene bag it should be opened to
allow the excess moisture to escape, and then closed again. Leaves will root
just as easily when potted into small pots of moist vermiculite.
Rooting in water
African violet leaves may also be rooted in water using a dark-colored
container such as a tablet bottle or a film cassette box of an appropriate
size. Clear containers should be avoided, as the cut end of a leaf petiole
will curl towards the brightest side of such a container. A small square of
aluminum foil is secured over the top of the container after it is about
three quarters filled with water. The trimmed base of the petiole is pushed
thorough a central hole in the foil, and should be positioned so it is barely
touching the water; it is therefore essential to top up the water level if
evaporation occurs. It is not advisable to allow roots to grow longer than
0.5in (1cm) before potting the leaf into a small pot of compost, as longer
roots are water roots and do not convert easily to compost roots. Leaves
with water roots when potted into compost do not proceed quickly to
plantlet production, in fact not until compost roots have grown; so the
time spent producing those long water roots has in effect been wasted.
Growing on
Roots should have grown in six to eight weeks, and you can test if they have
because then you will be able to lift the pot, leaf and compost all together by
holding just the leaf tip in one’s fingers. Plantlets should be starting to
show above the compost in a further six to eight weeks, though this will
depend upon the hybrid as some produce quickly whilst others can be very
slow. At times a leaf is reluctant to put up plantlets and will itself grow larger;
this sort may be encouraged to produce them by breaking off the upper half
of its blade. The number of plantlets that a leaf produces can sometimes be
amazing. On average the number is around four or five, although sometimes
a leaf will produce only one, but there are hybrids that are extremely prolific,
producing up to twenty and at times more. When this happens the heart
must be hardened into discarding a percentage of them and potting up only
the sturdiest. The wonder is that even after producing such a number the leaf
can be retrimmed, potted, and will produce plantlets once again that are just
as numerous and sturdy as the first crop.
When plantlets can be seen, and when watering is necessary, feeding
should begin with a very weak dilution -say, at one-tenth strength -of a
high nitrogen fertilizer such as fish emulsion. As the plantlets grow they
should be hardened off by gradually removing the propagator top or
opening the polythene bag daily for an hour or two, and be given a weak
foliar feed. When they are 1.5 to 2in (4 to 5cm) tall and each have a
minimum of four leaves, they are ready to be separated from their mother
leaf and potted individually into 2in (5cm) pots, with the exception of
variegated hybrids.
The potted plantlets should be stood in a tray lined with capillary matting
that has been thoroughly wetted and then wrung out. Initially they are
given a weak foliar feed to settle them into their new environment, and
after about three weeks the feeding programme is changed to alternating a
high nitrogen and a high phosphate fertilizer at one-eighth strength for
every watering, with an occasional watering of plain tepid water.
When the roots of young standard or large-sized African violets have
filled their pots, they are potted on into 2.5in (7cm) pots, given another
foliar feed, then three weeks later the same feeding programme is
followed as previously, using high nitrogen and high phosphate fertilizers.
They may be left in this size pot until budding is initiated, when they
should be potted on into 3.5in (9cm) pots. With miniature and semi miniature plants it is advisable not to pot on in the first instance but to
repot into a clean pot of the same size, gently teasing away a little of the
compost at the bottom of the root ball so that a small amount of fresh compost
may be added.  The maximum size of pot for miniature and
semi-miniature rosette hybrids is 2.5in (7cm) even when mature.
Odd Happenings – Do not be surprised to see a flower stalk grow from a
young plantlet whilst it is still on its mother leaf. It may seem odd, but it
happens sometimes and is not in the least detrimental.
Although the following happens infrequently from vegetative
propagation, a plantlet may be produced that does not have the appearance of its
parent or siblings in some way, either in leaf form or flower color and
form. This is a mutant or sport and should be labeled as such. Further leaf
propagation of this mutant should be carried out to ascertain whether or
not it is stable, and if it proves to be so, then it should be labeled as ‘Sport
of. ..’ and not given a new name.
Chimeras
This type of African violet poses a slight problem in its propagation
because it does not come true to pattern by the normal leaf method.
Plants grown from their leaves will rarely have flowers with the pinwheel
pattern, but are more likely to have flowers of a solid color. To explain,
chimera African violets have two genetically different tissues side by side,
an outer and an inner layer in the petioles. Normally roots and plantlets
grow from the inner tissue layer, therefore the original chimera is not
produced because the outer tissue layer, which must be in the make-up of
the propagated plant, is not in the plantlet.
There are certain leaves which may be used for propagation, namely
the usually insignificant two small leaves behind the inflorescence on the
flower peduncle. Flowers above these leaves should be removed so that
very short pedicel stubs remain -but without damaging the base of the
stubs -and the peduncle cut through about O.75in (2cm) below the tiny
leaves. This cutting is inserted into a small pot of moist compost or
vermiculite so that the leaf axils are level with the surface of the compost;
it is then treated as a normal leaf cutting. Minute plantlets will grow from
the axils of the two tiny leaves, and when large enough they should be
potted up individually and grown on as any other plantlet.

Propagating from a sucker or offset

Sometimes a rosette type of African violet will produce a tiny sucker or
offset in a leaf axil instead of a flower stalk. If allowed to continue to grow
in this position, suckers will cause a plant to become multi-crowned. However, if the
sucker is carefully eased away from the leaf axil when it has six to eight
leaves, it may be used to grow into another plant. Care must be taken that
no damage, or very little, is done to its rounded base when removing it.

A small pot is filled with moist compost, and a small hole made in the
centre surface; this is filled with damp vermiculite into which the sucker
base is inserted. As the vermiculite is sterile and without any food value,
roots grow quickly and spread into the surrounding compost. The sucker
should then be kept in a humid, warm and light position out of direct
sunlight, and grown on as a plantlet.

The quickest way to propagate a trailing African violet to get a
good-looking plant is by cutting off a short branch -which is actually an
elongated sucker -just above a leaf node and rooting it down in a pot of
compost and vermiculite as for a sucker. Because the base of the cutting is
a stem without leaves, it is much less likely to suffer problems in rooting.
Taking this cutting is also useful to the original plant, as its stem will then branch again.

The usual way of propagating chimera African violets so as to keep the
true flower pinwheel pattern is by sucker growth. Plants can be induced
to produce suckers from leaf axils either by carefully removing just the
centre growing point, or by beheading the plant. The latter method gives
a new plant quickly by being rooted down, and later suckers to increase
the number. It needs some courage for a fairly new grower to behead a
plant, but it is very worthwhile if chimeras need to be propagated. A
word of warning, however: extra care must be taken that the base of a
chimera sucker is not damaged in any way. A nice rounded sucker base
can be obtained if you remove the leaf below it early on, thus allowing
the sucker to spread out; then when it is of good size, a gentle sideways
tug will take it cleanly away from the main stem of the old plant. Don’t be
too greedy: don’t allow more than two suckers to grow on an old plant at
a time; they will then be much better quality for growing on. When they
are removed, others will probably grow from other leaf axils, and the old
plant will not be so stressed as to stop growing.

Propagating from seed

African violet seed is dust-fine and requires very careful handling before
being sown.

A small shallow pan such as a margarine tub, with drainage holes made in
the bottom and a layer of perlite in it about O.5in (1cm) deep, is filled with fine moist compost. It is stood in a dish of warm water until the compost
surface is seen to be thoroughly wet, when it is removed and allowed to
drain for at least two hours. The seed is sown very thinly onto the compost;
it should not be covered with more compost nor with fine vermiculite. Like
all gesneriads, African violet seed needs light to germinate. The pan should
be covered with clear plastic film to create a humid atmosphere for the
seed, and either kept in a warm, light position out of direct sunlight, or
placed under fluorescent lights. Alternatively, the uncovered pan may be
placed in a heated, covered propagator running at 70°F (21°C). When the
first sign of germination is apparent in three weeks or less, the pan should be
taken from the propagator, covered with clear plastic film and placed on a
window-sill out of direct sunlight or under fluorescent lights.

Do not start worrying if germination takes longer than three weeks.
The time it takes can depend upon how fresh the seed is, although it has
been known for seed as old as four years to germinate in six to eight
weeks. But sometimes apparently fresh seed does not germinate because it
is not viable. Always leave a seed pan for several months before giving up
on the seed and discarding it.

As the seedlings grow, great care must be taken that the compost does
not dry out; watering involves standing the pan in a dish holding 0.5in
(1 cm) of tepid water for ten to fifteen minutes to allow the perlite in the
bottom of the pan to soak up the water. Once the seedlings have four tiny
leaves they may be pricked out into quarter-size seed trays of moist
compost, and covered with clear plastic film. The exception to this is
with the all-white seedlings growing from seed of variegates: it is pointless
to prick these out because they will not grow any more as they lack
chlorophyll. However, all-green seedlings, or those with only a little
green in their leaves, will grow on to be variegates and should be pricked
out. When necessary water should be given from the bottom by standing
the seedlings in a dish, and a quarter-strength high nitrogen fertilizer
should be given at every other watering.

Once the seedlings are established and have grown so they touch the
plastic film, this should be removed gradually to harden them off. As they
grow on and their leaves begin to touch each other, the time has come to
transplant them into individual small pots -these should be of a suitable
size, in particular so they are not over-potted and do not have too much
compost for their roots. Keep them in a warm, humid atmosphere for a
few days so that they can recover from the transplanting. The seedlings
should now be fed with an eighth-strength balanced fertilizer at every
watering and grown on to maturity. Long before this the all-green
seedlings of variegates will be showing their full variegation potential.

Micro-propagation

Micro-propagation, or tissue culture, is a method used by commercial
nurseries to produce very many plants of a hybrid in a comparatively short
period of time. It is carried out in laboratories equipped with special
facilities for controlled sterile conditions. It is not a propagation method
that the average hobby grower at home is normally able to use.

The process entails a small section of an African violet leaf being
cleaned and sterilized with chemicals, and then placed on an agar gel in a
jar with a screw-down lid. The agar contains hormones and nutrients to
induce shoot production, and within a week or two the leaf section will
be covered with a multitude of shoots; it is then removed from the jar,
divided and replaced in more sterile jars containing the same formula agar.
Division continues until the number of shoots, which at this time do not
have roots, is considered adequate for the required plant production. At
this point all the shoots are transferred to sterile jars containing agar of a
different formulation, this having hormones and nutrients that will
promote root growth, and the shoots begin to grow roots. Sometimes roots
have been known not to connect with a shoot, thus making the shoot
useless. After about two months the agar is covered with a mass of minute
plantlets which may then be teased apart into individual ones, pricked out
into compost, and grown on into young plants under nursery conditions.

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