Propagating Ferns

Activity Tasks :  March 26th. We propagated spore collected from Dicksonia Antartica and Cyathea Cooperii. Ferns, being primitive plants, lack flowers and so reproduce by spores. Each spore case (housed in the protective sori on the leaflet of the fern frond) contains clusters of sporangia that hold the dust-like spores. To collect this fine spore, the fronds were kept previously in manilla envelopes in a warm, dry place. Spores of most temperate ferns ripen in mid to late summer. 

We prepared a growing media of two parts sphagnum moss peat and one part coarse sand of about 10 litres, mixing in about 2.5 L water - enough so that moisture could still be gently squeezed from the media. We used enough of this media to fill several plastic sealable tubs to a depth of about 3cm from the rim and then into a machine for pasteurisation. Following this we gave the tubs another gentle soak with a watering can before sealing the lids. 

We then gently sprinkled the spore over the surface of the media and again sealed the container, before placing it into a palstic bag to be tied up and stored in the propagating house. Hardy, cool-temperate ferns like Dicksonia can germinate at 15 -20 degress celsius. It can take anywhere between 2 - 26 weeks for the prothalli (the sexual, gametophyte stage) to form on the surface of the media.

OH&S issues : Sphagnum peat needs to be gently rubbed through a sieve, which can raise a lot of particle matter in the air and in large quantities aggravate the airways. As a safety measure we wore dust masks.

Environmental Work Practises/Considerations : Sphagnum peat is a finite resource and quite expensive. The peat we used was sourced from Holland. It is ideal for this type of propagation as it has an excellent water holding capacity and it has a low pH. It requires moistening before use. In the absence of a sterilising/pasteurising unit, the media can be treated by pouring boiling water over the surface. 

Ref :  RHS propagating plants

          Ferns from Spores handout