Thursday, April 19, 2012

Crows Nest Fern

Asplenium australasicum

Oh, the difficulties of rainforest photography!
Despite the poor quality, I couldn’t resist sharing this picture Of a crows nest fern growing on an old vine. Nature’s artistry sometimes achieves a composition that not the best landscape gardener can match!
The photo was taken at O’Reilly’s, but this plant can also be found in the rainforests on the edge of the Darling Downs.

Growing naturally on rocks or trees in rainforests, or sometimes on the ground (if the drainage is good), these hardy ferns can grow to more than 3 metres in diameter - the size of a small bedroom! They depend for their nutrients on leaves and other debris which are caught by this saucer-shaped plant. They tumble towards its centre where they lie and decay, releasing their component parts for recycling. Garden specimens, especially those grown where the natural spatter of falling organic matter is scanty, appreciate a small amount of good compost or leafmould placed in their centres from time to time.

 New fronds form in the centre, usually unnoticed until they begin to unfurl, refreshing the plant with a new rosette of shiny green leaves.


Old leaves are best left on the plant, as they form a skirt which shelters the roots from drying out.

If you buy a crows nest fern from a nursery, you might be getting this species, or you might get the very similar Asplenium nidus from North Queensland. It is worth growing the local species, as it is much more tolerant of drought and cold. We can find out which one we have by examining the midribs of the frond. In A. australasicum they are flattish above and have a sharpish keel beneath. The midrib of A. nidus  is rounded above and beneath.
These two species, between them, may well be the most commonly grown fern type worldwide. They are often grown in a pot or stump or on the ground in well-drained, high-humus soil, where they have room to form their magnificent circular rosettes. Attaching them to trees results in a semi-circular plant. It is said that a circular, adult plant can be cut in half for attaching to a tree or slab. I haven’t tried this, so would be interested to hear from any readers who have done it successfully.
Depending on your natural rainfall, a well-established plant in a shady, sheltered position may be able to manage without supplementary watering. A little extra water is always appreciated, however.
This plant is also native to South-east Asia, where the young fronds are cooked as vegetables. The fronds make a wonderful, long-lasting addition to floral arrangements.

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