Begonia Propagation Page
Propagation
by Brad Thompson
This page will describe the various ways to propagate
begonias through cuttings. Starting begonias from seed is covered
in another chapter so won’t be addressed here. Rooting cuttings
to form new plants is basically a type of cloning. To make new
copies of begonia hybrids, cuttings are the only way they can be
reproduced. It’s also an easy and quick way to make new plants of
begonia species. There are three basic types of begonia
propagation, stem cuttings, leaf cuttings, and division.
Propagation involves taking portions of a begonia plant
and rooting them to grow into new plants. Some types of
propagation require more skill than others do or more specialized
conditions. Everyone should be able to propagate begonias without
too much difficulty. The following pages contain descriptions and
illustrations of the various types of propagation. Nearly all
begonias can be started from stem or tip cuttings. Rexes,
rhizomatous, tuberous, and a few other types can be started from leaf
cuttings or portions of leaves. All begonias can be divided
except for some tuberous begonias.
Rooting Mediums and containers
The simplest medium to root cuttings in is water.
Nearly all the types of cuttings will root in water, except for leaf
section cuttings that require sterile conditions. The best
containers for rooting in water are small baby food jars.
Whatever container you use should be relatively. The reason for
using a small container is that cuttings release a rooting hormone in
the water as they root. The least amount of water, the more
concentrated the hormone. You can put several cuttings per
container. Once roots are half an inch long, they can be potted
up in regular potting mix and grown on. Forget any myths you’ve
heard about water roots, the cuttings will transplant just fine.
Other common mediums for rooting cuttings are perlite and
vermiculite or a combination of both. These mediums can be
used for cuttings including ones needing sterile conditions.
Perlite and vermiculite are rock/mineral products so contain no organic
matter that can harbor disease or promote rotting. When using
these products, you’re basically still rooting in water. They act
as little rock sponges to hold water for
the cutting to root in.
They also contain air pockets. Perlite and vermiculite don’t
require sterilization to use, although you do need to use distilled or
sterile water to keep it sterile. Vermiculite is less commonly
used now, I believe it was determined to contain asbestos. When
using either product, you should wear a mask or avoid breathing in the
dust when mixing or pouring it.
Another medium for rooting is peat moss or various combos
of peat moss, perlite, and vermiculite. This works for all types
of cuttings but unless sterilized for sure, it may rot cuttings since
it contains organic material. It is mostly used for stem cuttings
or rhizome cuttings that don’t require sterile or specialized
conditions. It’s also used for cuttings that are overly fleshy
and tend to rot in water only.
Many begonia cuttings can be started directly in your
potting mix in a shady location. Most rhizome, shrub,
thick-stemmed and canes will start directly in mix. You should
only use this method for the sturdier varieties though.
There are many clear containers such as sweater boxes that
work quite well for rooting begonia cuttings. Leaf and wedge
cuttings require some type of container to root in. It has two
benefits. It keeps the humidity up so the rooting medium doesn’t
dry out and is less stress on the cuttings. It also keeps spores
that cause disease from your medium.
Tip and Stem Cuttings
Tip cuttings are the most common
type of begonia cutting used. Nearly all types of begonias can be
started from tip cuttings, even rhizomatous. A tip cutting is
basically the end portion of a stem. It is removed from the
plant, rooted, then planted and grown into an exact copy of the
original plant.
A tip cutting has to have certain elements in order
to grow a good plant from it. As a general rule, begonias won’t
send out new growth from a node where they have previously had a
bloom. Nearly all begonias that won’t grow from leaves also won’t
send out growth from a node they bloomed at. This element doesn’t
apply to tuberous, rhizomatous and rexes, they will send out new growth
from any rooted part of the plant.
The illustration at the left shows a typical begonia
stem and it’s various possible components. On a begonia stem,
there is a node above each leaf. This node can have a bud that
will grow into a new stem someday, it can have a flower cluster grow
from it, or it can be dormant and not showing a bud. Any node
that doesn’t have flowers or the scar left after the flowers have
fallen off, has a bud in that node whether it shows or is completely
dormant and not showing.
A good cutting needs to have a node with a bud on it for
it to grow into a proper plant after it’s rooted and planted. The
bud is where all future basal growth will come from as the cutting
grows. Using cuttings where the nodes have had blooms will result
in plants that can never send up new basal growth. The
illustration shows how to determine what nodes you have. If you
look at a node and there is a leaf or the scar left after a leaf
has fallen off, and there is no scar left from a flower, then there is
a growth bud there whether you can see it or not. When leaves and
flowers fall off they both leave round scars on the stem where they
were. So, a bare node that has two scars is a node that
previously had a leaf and a flower cluster. If this explanation
isn’t clear, the illustration on this and the next page should
make it clearer for you.
The best cuttings are ones that have never bloomed
since they have buds in all their nodes that will eventually grow into
new stems and new side growth. Any stem cutting though, that has
at least one good bud in the lowest node will be a good cutting.
In the illustration you can see that the lowest node
pictured has a scar from where the leaf was attached. It also has
a bud. That is the main requirement of a good cutting, no matter
what the rest of the nodes on the cutting are.
A tip cutting should also have at least a couple
leaves. One without leaves may root but not as easily or as
quickly. You can also make a regular stem cutting from parts of a
stem that don’t have the tip. For those types of cuttings, since
they don’t have the tip, need to have at least two nodes with
buds. One at the base of the cutting that will be buried in the
potting mix and one to grow into top growth. It should also have
a leaf if possible. Woody hardened stems will root without leaves
however. They do take longer though.
The illustration at the below shows a good tip
cutting. It has buds in the leaf nodes for future stem growth as
described previously. When taking a tip or stem cutting cut the
stem about half an inch below the 
selected node. It’s possible that if you have
any stem rot while rooting the cutting, if you have cut closer than
half an inch below, you could lose that lower node. Half an inch
gives you some margin. Cutting further than half an inch below
leaves too much unneccessary stem below the lowest bud. When you
get ready to pot up the cutting after it roots, it will be hard to get
that lowest bud buried in the pottin mix if too much extra stem is left
below it. When rooting the cutting, you should remove any leaves
from the lower nodes first, since those parts will be buried eventually
anyway can could rot.
In the illustration below right you can see how to
pot up the newly rooted cutting. Put the cutting as low in the
pot as possible covering at least one good bud. In the
illustration,
you can see the importance for doing
this. The buried buds will eventually grow into new shoots and
all the future basal growth. Without a buried bud, the cutting
will of course still root and grow. It won’t be able to send up
new basal growth however. It will only be able to branch
somewhere above the pot.
The only time you should use cuttings without buds to bury
is if you’re going to grow a begonia as a standard. Since a
standard should be just one main stem, ordinarly bad cuttings are
perfect for that purpose.
For begonias that are everblooming and hard to get
good cuttings from, one tip is to first prune the plant. Then
take cuttings from the new growth that comes up.
Rhizome Cuttings
Rhizome cuttings are a type of stem cutting. Like
cane, shrub and other stem cuttings however, you do have to use cutting
with nodes. Rhizome cuttings can be made any length. In the
illustration the rhizome is cut into two inch sections.
Most rhizomes can be rooted directly into your potting mix without any special considerations. The rhizome
is fleshy and can easily maintain inself until roots and leaves
form. Some more delicate varieties such as rexes may do better if
rooted in an enclosed container though. Long rhizomes can even be
rooted in water like you would any stem cutting. They are
slightly more prone to rotting in water though since they are so
fleshy. Although leaf cuttings on rhizomatous types will give you
more plants in the long run, rhizome cuttings will give you a new plant
faster. It’s a good method for those that just want another plant
or two and aren’t worried about producing larger numbers of
plants. The rhizomes don’t have to have leaves to root and
grow. When using the tips of rhizomes remove the largest leaves,
they’ll probably fall off during rooting anyway. Make sure the
rhizome has good contact with the rooting medium but not buried more
than half way. Tip cuttings from rhizomes can be rooted
upright with the cut end stuck one half to one inch into the rooting
medium.
Leaf and Wedge cuttings
Many types of begonias will start from leaf
cuttings. These are mainly rhizomatous, rexes, and tuberous
begonias. With nearly all begonias you can root a leaf, but only
certain types will then send up a new plant from the rooted leaf.
With begonias other than the three types mentioned, consult with other
growers about specific plants that may start from a leaf.
Exceptions to the only rhizomatous and tuberous starting from leaves
rule, are begonias such as B. luxurians and some of the mallet type
canes.
Types of leaf cuttings
All parts of the leaf are capable of rooting and
forming a new plant. The only requirement is that the leaf
portion contain a main vein. There are three main types of leaf
cuttings. A full leaf cutting, wedge cuttings, and cone cuttings.
If your purpose is to create a number of plants, you may choose to do
wedge cuttings since you can make many wedges from a single leaf.
If your purpose is just to propagate a couple of new plants for
yourself, you may choose to just use whole leaf cuttings.
Cone cuttings are slower than regular whole leaf cuttings but since
more veins are exposed to the rooting medium, the resulting plant is
much fuller.
Materials required
There are several basic requirements needed for starting
leaf cuttings. You need warmth, good light, humidity, and a
sterile moist medium.
Light and warmth
This is best provided by using fluorescent lights. A
light stand, besides providing constant good light, also provides
suitable warmth. Any area you can keep reasonably warm will work
however. If not using lights, you need an area with bright light
but no sun. Since leaves need to be rooted in covered containers,
any sun will overheat and cook the cuttings. Under lights, you
can keep the lights as close to the top of the container as
possible. Leave the lights on for at least 14 hours a
day. You can leave them on continuously if desired.
Containers
Most leaf cuttings need covered containers to root
in. The purpose is to keep the humidity high and also to keep the
medium sterile. The container can be as simple as a clear plastic
cup covered with saran wrap for single cuttings or an expensive tray
with a clear dome. You can even root leaf cuttings in zip lock
bags. If you’re lucky enough to have a greenhouse, you can root
leaf cuttings out in the open under a misting system. Even in a
greehouse though, you may choose to use covered containers for ease of
use.
I know several growers that root in zip lock bags with
individual bags for each cutting. One grower I know stapled the
bags to the wall in out of way places during warm weather. For
especially rare or hard to grow varieties, I usually do provide those
cuttings their own container. I put the rooting medium in a
small pot then put the pot into a zip lock bag after the cutting is in
it.
Trays with domes or clear sweater boxes work very
well. You can even use aquariums left over from your fish
experiments. There are also a myriad of different clear sandwich
or food containers to choose from.
You can either use the medium directly in the tray or use
individual pots of medium for each cutting then set in the tray.
Both have advantages and disadvantages. Just filling the tray
with medium is easier and can be refilled over and over. However,
in my experience if you root this way you end up with parts of the tray
and different varieties of begonias growing at different rates.
You usually end up with half of the tray potted up already and the rest
still waiting. If you propagate continuous and keep refilling the
tray as you take things out, it will work fine though. Another
disadvantage is getting or keeping the medium to the correct dampness
without being too wet. It’s also hard to keep the cuttings
separated by variety as they grow unless you’re careful to make clear
separations and labeling.
Using individual small pots for each cutting works well
because you can move cuttings from box to box as needed. If
you’re using several boxes as things get potted up, you can recombine
the slower rooting cuttings into one box. The disadvantage is
that it is more time consuming filling all the individual pots and
making separate labels for each. If you don’t mind the added
time, it’s the better method though.
Rooting mediums
for leaf cuttings
The most commonly used medium for leaf cuttings is
perlite. It is already sterile and holds the correct moisture
without staying too wet. It’s only disadvantage is you have to
check often to make sure it doesn’t dry out. Any medium
such as peat moss, vermiculite and combos will work fine as long as
they are made or kept sterile and kept to the right degree of
moisture. I have used all the various mediums with good success
but find perlite the easiest and best to use.
Another less common medium for rooting cuttings is called
Oasis(TM). This is similar to the Oasis used for floral arranging
but comes in form specifically for rooting cuttings in. It is
made a size to fit the most common tray size. It has individual
one inch cubes with a hole in the center of each to insert the cutting
in. The Oasis can be cut easily to fit any container
though. Don’t try using the floral Oasis for this purpose, it
isn’t made for rooting cuttings like this other product is.
The oasis is soaked in water till it has soaked up as much water as it
can, then drained. It already contains fertilizer so
nothing needs to be added to the water. It’s already sterile so
also doesn’t need to have anything extra done to sterilize it. I
have used it successfully many times and it works especially well for
wedge and small cuttings. It was designed so that after the
cuttings are rooted you cut the cubes apart and plant the cube and all
in your potting mix. This design however doesn’t work for
begonias. If the cube is left on the cutting the plant will
usually not thrive or die later. The cube either wicks water to
the surface of the mix so causes a dry spot, or stays too wet and
causes the plant to rot later. Examination of the roots on plants
that failed showed that the roots all stayed in the oasis instead of
growing out of it into the mix. For this reason, you must
remove all the Oasis from the rooted cutting before potting them
up. This usually results in some root loss, besides being time
consuming. However it is easy to use so does have its uses for
some growers.
Other items
you’ll need
One item you’ll need is something to cut the leaves
with. You can use a knife, scissors, or pruners. The best
cutting tool to use is a razor blade. There are several
reasons. Using a new blade means you have a sterile utensil that
doesn’t have diseases from your plants outside. If you use your
pruners, you’d have to sterilize them. The main reason though is
because it makes a very clean precise cut. If you use scissors or
pruners they don’t cut cleanly and crush the edges of the
cutting. This makes the cutting less able to draw up water.
Using the razor blade cuts cleanly without crushing cells along the
edge.
You’ll also need something to sterilize the cuttings
with. It doesn’t matter how sterile your medium is if the
cuttings you put into have spores of disease on the leaf surface.
The most common disinfectant for using on cuttings is a five percent
bleach solution. I have also heard of using a peroxide solution
but haven’t personally tried that. I have also sterilized
cuttings by dipping them in a fungicide mixed to the recommended
strength on the bottle. I let them dry, then rinse with water
before using. Make sure to wear gloves. You can also use
Physan(TM) following the directions on the bottle. I usually
spray my tray of cuttings with a fungicide after they are done just to
make sure nothing was missed.
Whole Leaf Cuttings
A whole leaf cutting consists of a leaf with a portion of
the leaf petiole (a petiole is the stem-like structure that holds a
leaf to the plant stem). You should leave the petiole about one
half to one inch long for rooting. When taking the cuttings leave
the petiole long until just before you’re ready to put it in the medium
so that the cut is fresh. Leaving the petiole too long won’t hurt
anything. However, it will take longer for the plantlets to come up
after rooting since they’ll have to come up from deeper in the
medium.
In the illustration below you can see a whole leaf.
The best leaf cuttings are young leaves but any leaf will work such as
damaged leaves you have to remove anyway. If the leaf is small
you can just cut the petiole and insert it into the rooting
medium. Larger or damaged leaves you should cut down as in the
illustration leaving a round center of the leaf with the petiole.
The remaining part of the leaf can be discarded or used for
wedges. The reasons for cutting the leaf down is that it takes up
less space in the tray and because the petiole will have less leaf to
support. The cut down leaf will have less leaf surface to
transpire from so the petiole won’t have to provide so much
water. Even if making wedges or cone cuttings, save that middle
portion as an extra cutting. On difficult varieties, that portion
will usually root, even if your wedges fail.
Whole leaf cuttings can be started without enclosed
containers for some of the sturdier varieties. You can leave the
petiole slightly longer and root them in small jars of water. You
can also fill the small jar with perlite and add water. The
second method does support the leaf better. You can also use pots
of perlite set in a shallow tray of water. If you use any of
these methods, don’t cover the container since the cuttings will
usually rot with all that water if covered. It does take
practice and experience to find out which varieties of begonias will
work with which methods.
Wedge Cuttings
Wedge cuttings are the easiest way to start many plants at
a time with the least plant material. It’s especially useful for
rare begonias or begonias that only have a couple good leaves to
use. In the 
illustration you can see how to cut a leaf into
wedges. A wedge is simply a portion of leaf with a vein in
it. You can make your wedges as small or as large as you
like. Smaller wedges may not survive if your conditions are less
than perfect. I usually make my wedges about an inch or inch and
a half long.
For wedges, conditions must be as sterile as
possible. As stated earlier in this chapter, a razor blade is the
best utensil to use for cutting. Perlite is the best medium for
rooting wedges. Add a very slight amount of fertilizer so the
plantlets have some food when they start to grow. You can fill a tray
with perlite and premoisten. When perlite is wet it becomes very
solid. I use a knife or plant label to make rows of small slits
in the perlite the right size to fit my wedges. The wedges can be
touching or overlapping so don’t be afraid to pack them closely.
Usually about half an inch to and inch apart works well. Try to
insert the wedge as upright as possible. Also make sure to label
carefully and keep different varieties separated. Try to mix the
tray up so that varieties that aren’t a similar color aren’t next to
each other so they don’t get confused later. They do require a
covered container.
Wedges may take a couple months to form roots and
plantlets. Check the moisture of the medium regularly to make
sure it doesn’t dry out. Misting occasionally with a weak fertilizer
for foliar feeding will 
help them along. You may want to leave
the cover opened slightly till they dry off a little before closing
tightly. Using distilled water will make sure that you don’t
introduce any diseases into your sterile environment.
As soon as little plantlets have come up and are large
enough to handle they can be potted up individually into small
pots. The illustration at the left of this page shows the new
plantlets coming up from a leaf cutting and wedge cutting. For
the first transplant they should remain in a covered container.
Treat them as you would seedlings of the same size. Once they have
filled the small pot and are ready to transplant again, you can harden
them off and move to other locations.
Cone Cuttings
Cone cuttings are similar to wedge cuttings. You cut
the center portion out of the leaf but instead of cutting it into
sections, you leaf it whole. You wind it around to form a cone
and insert into your rooting 
medium. Make sure to also put some medium
inside the cone. On the page are illustrations showing how
to do this.
The advantage to cone cuttings is the full plants
you can get from this type cutting. Plantlets will come up from
all the vein ends along the
bottom of the cone resulting in dozens of
shoots. If left together, they quickly grow into one full
plant. They can also be separated or cut apart to make many
smaller plants after rooted and plantlets have formed.
On all the various leaf cuttings discussed in this chapter
after plantlets have formed you can either pot up the cutting along
with the plantlet or you can remove the plantlet and use the cutting
over again. Some cuttings will send up plantlets several times
before they run out of energy if reused.
Mallet and Heel Cuttings
These types of cuttings are not commonly used but they do
have purposes. There isn’t much 
difference between the two and the mallet has
less chance of errors or rotting so you shouldn’t use the heel version
unless you have a specific purpose.
A mallet cutting will allow you to make a type of leaf
cutting from plants that ordinarily won’t start from leaves.
Since the leaf cutting contains a portion of the stem with a growth bud
it can be used for any type of begonia. It’s mostly useful for
creating as many plants as possible of a certain variety. Say you
have a cane with one stem that has several nodes with good buds.
If you propagate by stem cuttings you might only get one or two
cuttings. By using mallet cuttings you may get a dozen, depending
on how many nodes and leaves there were. Varieties of canes that
drop their leaves easily may not be good candidates because the leaf
may separate from the stem before the mallet roots. Treat mallet
cuttings as you would whole leaf cuttings following the same
procedures. After rooting a shoot will grow from the bud on the
cutting.
The following are two articles
from the July/August 1996 issue of
the Begonian,
official magazine of the
American Begonia Society.
Although most items were covered in detail in the article above you may
find additional info in these short articles
TIPS ON PROPAGATING BEGONIAS
by Barbara Berg
Most begonias can be easily propagated if a
few simple rules are followed. The materials required are inexpensive.
PROPAGATING MEDIA
Use the ready-mixed potting media available in plant stores such as
Jiffy
Mix. Sure-fire Mix. ProMix and Reddi Earth; mix your own of perlite,
vermiculite
and peat or sphagnum moss, or use sand, sphagnum moss, perlite or
vermiculite
alone. A little experimentation will help you find the one which works
best for your conditions. I use sphagnum moss, (long fiber, not milled)
for some tender begonias, or a prepared mix for most varieties and
species.
CONTAINERS
The important requirement of your propagating equipment is that it be
able
to comfortably hold the media, the cutting, provide the needed
moisture,
drainage and hold humidity in its environment if necessary for the more
tender varieties. Sweater boxes, pots with sheet plastic covers or
Wardian-type
cases are all appropriate.
CUTTINGS:
With
a few exceptions most begonias will propagate from any type cutting.
The
most important exceptions are that cane and semperflorens are not
satisfactorily
rooted from leaf cuttings. Semps are most successfully propagated from
well branched stem cuttings. If you do not use branched cuttings you
will
end up with a ~totem poles which wilt never be a satisfactory
plant.
STEM CUTTINGS Using
clean scissors or a knife cut about three to six inches of stem or
branch
of your plant depending on Its growth habit. Remove flowers, buds, and
any lower leaves which would be in the rooting medium. Dip the stem in
rooting hormone (Rootone) and insert from one-half to two inches into
the
damp not wet) medium. You may or may not need to cover them depending
on
conditions in the area in which your plants are grown.
RHIZOME CUTTINGS
Rhizomes are modified root stems of varying sizes. With a clean knife
cut
the rhizome in pieces with one or more Isaves, dip in rooting hormone
and
place the pieces at a slant in the medium. In some cases rhizomes with
no leaves can be laid flat on the mix and rooting will occur. Some
plants
can be divided with rooted rhizomes cut from the parent plant and
potted
directly. With all rhizomes be careful of over watering and causing the
rhizome to rot.
MALLET CUTTINGS Mallet
cuttings are taken from the plant to include a leaf or branch and a
portion
of the main stem on each side of the cutting. Dip the cutting in the
rooting
hormone and insert in the medium with the leaf or branch upright. Canes
and branching begonias propagate very satisfactorily using this type
cutting.
LEAF CUTTINGS
Using single leaves with a short stem (an incn or less) dip the stem
end
in the rooting hormone and insert the tip Into the medium. Larger
leaves
can be trimmed to smaller size to make them easier to handle. Rex
begonia
leaves can be cut in multiple places across the leaf veins and laid
flat
on the medium to produce plantlets at each cut.
WEDGE CUTTINGS
Leaves can be cut into wedge shaped pieces with the center of each
wedge
having a sizeable vein, dipped in the rooting hormone and inserted at
an
angle into the medium. Rexes are rooted commercially in this manner and
with a minimum of care it is almost fool-proof.
POTTING THE NEW PLANT When
the new plants appear and have an adequate root growth, transplant them
to an appropriate size pot. Over-potting will rapidly kill your plants.
A 2 to 3 inch pot will most probably be adequate and re-potting will be
necessary in about six weeks or so. Pot the plant in successively
larger
pots (one inch at a time) each time the root ball is the full shape of
the pot, or until the plant is the size which makes both you and it
comfortable.
Rooting Cuttings
The Art
of Proper Cuttings
by Brad Thompson
This article will describe the different types of cuttings you
can take for specific types of begonias and also the different rooting
methods for each.
1. Canes and Shrubs: Canes
and shrubs are usually started using stem cuttings ( a tip cutting is a
stem cutting also ). Any part of the stem that has growth buds will
make
a good cutting but the easiest part to use is the tip cutting with a
couple
of leaves. These can be rooted the easiest in plain water in small
jars.
My theory on using the smaller jars, and the reason they seem to work
better
is that the cuttings produce a hormone into the water to cause roots to
form and a larger jar dilutes too much because of the larger ammount of
water. If you root in water, pot up the cuttings when the roots are
about
a half inch long. Tip cuttings can also be rooted directly into regular
mix or a peat/perlite mix with relatively good success. Bury at least
one
good growth node under the mix and water as you would a growing plant
but
don't allow to dry completely out ( don't go overboard the other way
either
and keep soggy wet all the time ). Enclosing in a container under
lights
with warmth will cause them to root faster but make sure to use a
sterilized
mix to avoid fungal diseases. You can also root in plain moist perlite
in a covered container. If the weather is warm the cuttings should be
rooted
in 3 weeks to a month. Old canes or stems that you would ordinarily
throw
away because they are woody and don't have any leaves can also be
rooted
but take a lot longer to root and produce plants. Cut the stems so that
each has two or three good growth buds and stick them into mix burying
one node. I use a flat and stick them in rows. Some will not make it
but
since you would have thrown them away anyway you don't have anything to
lose and the flat can be stuck under a bench to root. Most canes and
shrubs
as a general rule will not grow from a leaf cutting. They will root but
they won't send up a new plant. There are only a couple of exceptions
to
that rule.
2. Rhizomatous (and Rexes):
Rhizomatous begonias will form plants from cuttings taken from any part
of the plant. The easiest way is to root rhizome cuttings (stem
cuttings
) taken from the tips. You can also cut long rhizomes into one or two
inch
long chunks to root. These are best rooted by pressing into moist mix
such
as a peat moss/perlite mix leaving the top half of the rhizome exposed.
Put into a covered container under lights or in a warm shady spot.
Rhizomatous
begonias can also be started from leaf cuttings or even pieces of
leaves.
Smaller leaves or cut down larger leaves can be rooted in water. Leave
two or so inches of stem on each leaf and put in small jars of water to
root. When you see small plantlets start to form or at least some roots
they can be potted into mix to continue growing. Bury the roots about
half
and inch to an inch deep whether little plantlets have started to form
or not and within two or three weeks little plantlets will push up
around
the leaf. Don't worry about buringthe
little plantlets but make sure to use a soiless mix such as a
peat/perlite
mix or they will rot and will have to reform. They can be separated
later
and put into regular mix or they can be left together to make a larger
plant faster. The leaf cuttings can also be rooted directly into peat
or
perlite in a covered container. Rhizomatous leaves can also be cut into
triangular wedges with a vein in the center and rooted in peat or
perlite.
These will take a little longer to root but will produce more plants
per
leaf. Whenever rooting in an enclosed container make sure not to
overwet
the mix and make sure everything is as sterile as possible. (refer to
growing
seed articles for who to sterilize your containers ).
3. Trailing:
Trailing begonias can be rooted exactly like the cane or shrub begonias
but wait until after blooming if you want blooms on your plants since
they
are seasonal bloomers as a general rule. They make better plants if
after
rooting you put 3 cuttings into each pot to grow on and pinch the tips
to make them branch.
4. Tuberous: Tuberous
begonias can be rooted either like canes and shrubs or like
rhizomatous.
They will grow from leaves. Make sure to start cuttings early because
they
have to have enough time to form a new bulb before they go dormant in
the
fall. You can try rooting them under lights later in the year and
growing
them through the winter indoors. This will work with some varieties.
Semi
tuberous do not have to form a bulb and don't go dormant so you don't
have
to worry about starting them so early. These are usually only started
from
stem cuttings because they have so many stems that leaf cuttings aren't
neccessary.
5. Thickstemmed:
Thickstemmed begonias usually start best rooting directly in mix. The
stems
are so thick and hold so much water that they usually rot when you try
to root them in water unless you're using small tip cuttings. Those
root
fine in water.