Another way of obtaining
plants is through bulbils or babies on the mother plant itself. There are
groups of ferns such as Diplaziums, Aspleniums, Tectarias, and a new subgroup of
Tectarias: Pleocnemia and Heterogonium that produce offshoots on the
fronds. These latter genera are represented in cultivation by Pleocnemia
irregularis and Heterogonium pinnatum.
A definite way of propagating,
though time-consuming is by way of spores. Since all ferns produce spores,
this method is most promising. However, growing from spores requires
patience.
There are a number of methods
used by a number of people. What works for me is outlined here.
The first step in propagating
from spores is to select viable spores. This is best done by removing a
frond that has mature spores. This is best done by observing how the sori
look. If they are plump, it is a good bet that the spores are ready to
dehisce. In looking for good spores, you will find, depending on the
genus, that the color of spores varies greatly. In many Polypodium
species, they are yellow. In Bolbitis, they appear black. There are
some green spores, usually found in plants such as Platycerium wallichii, and
capturing them is very tricky. But generally, removing a frond from a
plant and putting it on a sheet of paper out of a draught should yield
good spores.
Spores need a germinating
media, I prefer a commercial brand (Fafard 3B). I sterilize my media in a
bowl in the microwave oven for a couple of minutes. (Sterilizing the media
too long renders the mix useless.) After the mix has cooled down, I put
the mix in small plastic containers that have good fitting lids. I use tap water
(I have used rain water, and purified water, but I am not sure of a positive
effect) to wet down the mix and distribute my spores).
To go back a bit, once the
spores have dehisced (shed) there will be considerable debris on the paper.
The majority of what you see are shed sporangia--the spores were inside of these
cases. Now you must separate the sporangia from the spores which are
considerably lighter and definitely smaller. By tapping the paper, you can
separate the two. The sporangia, because of sheer weight, will move, thus
leaving the spores behind.
Once you have the spores
separated, it is easier to hold the paper above a container with the sterilized
mix and gently blow the spores onto the dampened media. One of the
greatest problems in sowing spores is to make sure they aren't sown to thick.
Once the spores are sown, cover the containers and wait. The container
should be put in an area of good light. I use artificial lights to grow.
If you have sown the spores successfully, there will be gametophytes within 4
weeks. As these grow it is not immediately necessary to water them.
Because of the sealed container, the plantlets are living in a 'terrarium' and
at this stage need no extra attention.
As the gametophytes change
into sporophytes, it will be necessary to separate the small plants in order to
give them room to grow. You should try using the same type of media when
transplanting sporelings. Try not to keep them out of the containers too
long because they will dehydrate.
The sporelings will now take
several months to grow and eventually they can be removed from the containers,
however this has to happen over several weeks. The sporelings have been
growing in an environment of 100% humidity and they must now face the outside
world with less than perfect ambiance. It is possible to remove the lids
slightly over a two week period. During this time, you probably will have
to occasionally mist the sporelings.
This process is called
'hardening off" the plants. After you believe that the sporelings are
thoroughly acclimated, pot them up as usual.