© 2019 by Inwardout Studio

  • Gabrielle Stannus

Proliferating plants

I have been stuck indoors for way too long over the Tasmanian winter. With writing and other deadlines keeping me tied to the computer, I have been itching to get out and continue with a little propagation experiment I started this time last year.

A golden oldie! Written by NA Wakefield and printed by the Field Naturalists Club of Victoria way back in 1975.

Living in a cool temperate rainforest, it is not hard to be inspired by your surrounds. I have been wanting to propagate ferns growing on the block where we live to experiment with in green wall plantings and other crazy ideas, e.g. kokedamas. Finding a copy of 'Ferns of Victoria and Tasmania' on my dad's bookshelf, I got to reading and learnt that there are some fern species that are relatively easy to propagate, i.e. you don't have to go to the trouble of collecting and germinating spores to grow them.

One such plant is Polystichum proliferum, commonly known as the Mother Shield Fern. According to the University of Tasmania's 'Key to Tasmanian Vascular Plants', P. proliferum is the only member of this genus in Tasmania and is often confused with immature plants of Dicksonia antarctica (Man Fern or Soft Tree Fern). D. antarctica does not possess the obvious dark brown scales on the underside of its leaves. This common and widespread ground fern can be found in wet forests in Tasmania, as well as eastern New South Wales and Victoria.

One of the most interesting features of P. proliferum is its ability to reproduce via bulbils, small plantlets growing from upper parts of its fronds. You carefully layer bulbil-bearing fronds onto the ground and fix them with pegs until rooted or removed and then place them in pots.

You can see the bulbil growing here on this Polystichum proliferum frond. It is a lighter green colour compared to the dark green frond supporting it.

Today, I finally got around to giving this propagation technique a go myself, well actually it is the second time I have attempted this, but more on that later.

Setting off into the forest to find me some ferns!

I did it slightly differently to what was recommended above. Rather than pinning down the fronds directly onto the ground, I used a fencing pin to hold each bulbil-bearing frond onto a pot containing a blend of orchid/bromeliad potting mix.

Pinning the frond down with a pin. Make sure that the bulbil is located centrally in the pot and has contact with the potting mix without the frond being under too much tension.

I then watered each plantlet in with a little Seasol, ostensibly to help the bulbils kick start the development of their roots, and left them in situ, i.e. still attached to their mother plant in the bush sans protection from the wildlife (fingers crossed!).

Grow, baby, grow! A dash of Seasol for good measure. Note that I have propped up this pot so that it hopefully stays in place and is not knocked over by the resident wombat.

This is not the first time that I have attempted to propagate P. proliferum from a bulbil. This time last year, I used a slightly different technique removing a segment of frond to which a bulbil was attached, then dipping it in rooting gel, before placing it in a pot filled with standard potting mix. You could place similar frond segments into moist sand in a punnet or tray and keep moist until roots have formed, when they can be potted on or planted out. I just decided to see if my way would work and save time. The result? Check out the little baby in the image below!

This is the Polystichum proliferum that I cut from its mother tree last year, potted up and then housed on our balcony. Despite its exposed location, this fern seems to be doing quite well. Notice the new fronds growing (lighter green in the middle). You can also see the original frond on which this plant was first growing as a bulbil (brown dying fronds). I probably should remove those fronds now as it looks like they have been exhausted of all nutrients now.

Where to from here?

My next experiment? Propagating the Microsorum pustulatum (Kangaroo Fern) that grows on the trees (epiphytically) and rocks (lithophytically) along the creek on this block. These ferns can be propagated by layering the growing points of their rhizomes and then removing carefully the portions that have formed fresh roots. I thought I would give propagating this fern a go last year. However, I made one fatal mistake.

After potting up the M. pustulatum rhizome sections I collected (more accurately, my dad collected), I left those pots outside in plain view of the local wildlife. Not surprisingly, they (most likely Bennett's Wallabies) decided that there is such a thing as a free lunch and nibbled those ferns before they could grow on. I have vowed not to make the same mistake this time!

So here's hoping my new little P. proliferum babies will proliferate in peace until the time comes when they can be potted on.

Heading back up the hill ... job done ... for now.

A bientôt!

PS. Special thanks to my little helper Celeste for taking all these photos xxx