Growing ferns from spores
The fern life cycle
Ferns do not flower but reproduce sexually from spores.
There are two distinct stages of the fern life cycle. Mature plants produce
spores on the underside of the leaves. When these germinate they grow into
small heart-shaped plants known as prothalli. Male and female cells are
produced on these plants and after fertilisation occurs the adult fern begins
to develop.
Collecting spores
To collect spores place a portion of mature frond on a piece of paper in
a dry place. If spores are ripe they will be shed onto the paper and will
appear as black, brown or yellow 'powder' which is a mixture of spores and
fragments of the spore cases (sporangia).
Sowing method
It is important to sterilise the germination mixture before sowing the fern
spores by pouring boiling water over it This kills the spores of fungi and
other plants that may germinate and crowd out the developing fern prothalli.
Spores should be sparsely sprinkled on a medium such as finely chopped tree
fern fibre, peat moss or sphagnum moss. Equal parts of loam, peat moss and
finely crushed terracotta spread to a depth of 2cm over a base of vermiculite
also forms an excellent germination base.
Once sown the containers should be covered with plastic or glass (allowing
some airspace) and kept at around 20 degrees C in indirect light. Spores
take from 2 to 6 weeks to germinate.
Potting on
After a few weeks the germinating spores appear as a mossy growth. When
the prothalli are formed and well developed they may be pricked off into
a punnet containing a finely sifted soil mixture. The container should be
covered with glass or plastic until the fronds appear. The developing ferns
should not be exposed to direct light.
Further potting up should be into a coarser textured mix with relatively
high levels of organic matter. The mix should drain well. Materials such
as sharp river sand and gravel-sized charcoal pieces may be useful for this purpose.
Written for an ANBG leaflet by Rod Harvey
Prepared for the internet by Murray Fagg
Updated ,
Murray Fagg
(anbg-info@anbg.gov.au)