I am trying to grow
all the species of begonias of section Gireoudia and have just
received an order of 15 packs seeds from the French Association of
Amateur Begonia Growers.
Begonia seeds are very small, ranging in size between, 0.2mm 2.3mm
[Tebbitt 2005] the packet of seed in the picture below will contain
approximately 200+ seeds. [image 1]
The technique for
planting seeds for all types of begonias is basically the same.
There are several guides for planting seeds on this website and that
of the ABS and
AABS. This is what I do:
following items: small plastics pots [5cm]; scissors; potting
compost; tap water; cling film; plant labels, indelible pen and
begonia seed. [image 2]
Wash your hands
2. Clean/sterilise your tools, pots. Again there
are several methods described on this site and the ABS and AABS
websites. My preferred method is to wash pots in hot soapy water to
remove large particle of potting medium, then, I put them through
the dish washer.
3. Fill the pots with a commercial sterile peat
based potting compost. I'm using seed compost from Wicks at the
moment. It is important to use a sterilised pot/scoop to fill your
pots so that you don't add contaminants to your pots or your bag of
compost. I am using small pots because I only want to grow a few
plants of each species.
4. Tamp down the compost gently again I use the
bottom of a sterilised plastic pot.
5. Place the pots on a tray and water with tap
water. I always tap water as it is treated with chlorine in the UK
and this will kill fungal and bacterial elements which can cuase to
damping off. Cover the top of the pots and leave to drain for
6. Then I cover the top of the compost with a
sprinkling of vermiculite. The theory is that the vermiculite draws
off excess water from the compost by capillary action and so
provides the ideal moist environment for germination. I'm not sure
this really makes any difference.
7. Sprinkle a little seed on top of the
vermiculite. Do NOT cover the seed with soil /vermiculite as begonia
seed needs light to germinate. Unless you want to grow a lot of
plants [e.g. for summer bedding] you only need a pinch of seeds.
8. I then seal each pot in cling film and place in
a propagator at 16 21ēC under light source on a timer to give 12
14 hours of light a day. I'm using an ordinary domestic double
florescent strip as a light source. An east or west facing window
sill should give sufficient light for germination, but, you will
have to plant in the spring and summer months. Using an artificial
light source gives me much greater flexibility. [image 3]
9. Label each pot. If planting more than one
species label each pot as you go to avoid labelling errors. All
begonia seedlings look the same, initially, it takes some weeks
before they start to differentiate.
10. Wait 10 14 days for germination although
some species may take longer]. [image4]
My Begonias from
Mexico and Central America flower between December and April and
most of them are starting to produce flower spikes. [image 5]
This is a good opportunity to propagate plants by seed. Pollination
of female flowers is required to produce seed. A feature of all
begonias is separate male [image 6] and female [image 7]
flowers. Identifying the male and female flowers is simple the
female flowers have a swollen area proximal to the petals the are
the ovaries and often have wing structures. Pollination being the
transfer pollen from the anther of the male flower to the stigma of
the female flower. It is always better to cross pollinate two plants
of the same species, but, it is acceptable toself pollinate plants.
There are several methods to do this. My preferred technique is to
pick the male flowers fold back the petals exposing the stamens.
[image 8]. Then brush the pollen over the stigma of the female
flowers. Pollinated flowers will loose there petals and the ovaries
will swell. The seed pod will mature and dry out over the following
weeks. When the pod is dry it can be harvested from the plant and
cut open and the seed emptied onto a sheet of paper being careful
not to include pieces of the seed pod. The seed can then be planted
or put in an envelope, labelled and stored. [image 9]