Cyathea cunninghamii TASMANIAN FERNS 
 

Ferns are fascinating covering, in many different forms, thousands of species throughout the world. In 19th century Britain an upsurge of interest occurred and an amazing number of types were brought into cultivation and research into growing and propagation reached an all-time high, to such an extent that the earlier writings form the foundation of studies today. The ferns of Tasmania are an important part of Tasmania's vegetation. There are ferns in nearly every part of the island, ranging from wet, shady rainforests to coastal cliffs and all parts in between. There are over 100 ferns and allied plants and these are collectively known as Pteridophytes. The name is from the Greek ‘pteron’ meaning a wing. These are segregated from other plants because they are flowerless (unlike angiosperms) and do not produce seeds like gymnosperms (e.g. conifers). 

Ferns possess a vascular system, which transports water and nutrients through the plant, and this distinguishes them from other non-vascular, lower order plants like mosses and liverworts, lichens, fungi and algae. Ferns reproduce from spores and have separate (free-living) gametophyte and sporophyte generations. When the word "fern" is mentioned, most people will imagine a dark green plant in a cool, wet rainforest. However they can grow in a variety of climates and substrates. Terrestrial ferns grow in the soil, lithophytic ferns grow on rocks, and epiphytes grow on rotting organic matter and tree fern trunks. There are Tasmanian ferns growing in full sun and in very dry conditions, for example Pteridium and Cheilanthes. There is also Asplenium obtusatum, which grows on coastal cliffs and gets battered with salt spray, and there are aquatic ferns that float on the surface of fresh water ponds and streams.
 
CULTIVATION. There are numerous Tasmanian ferns suitable for cultivation, the most popular being the common tree fern Dicksonia antarctica. Other suitable species are Polystichum proliferum, Blechnum nudum, B.wattsii, B.penna-marina, B.fluviatile, Doodia australis, Todea barbara, Histiopteris incisa, Asplenium bulbiferum, Rumohra adiantiformis and Cyathea australis. Tree ferns such as Cyathea australis (Rough Tree Fern), Dicksonia antarctica (Soft Tree Fern) and Todea barbara (King Fern), are very slow-growing and take many years for the trunks to attain height but, like many ferns can be grown successfully in containers enabling them to be moved into more sheltered environments according to the season.  Blechnum nudum
        Blechnum nudum
Doodia australis
        Doodia australis

Blechnum penna-marina v alpina
           Blechnum penna-marina v alpina

SOIL The natural habitat of ferns involves decaying organic material, assisted by the action of soil micro-organisms, which provides the slow release of nutrients required, plus abundant water. Well decayed leafmould, peat moss and turfy loam produce all the parts of the food needs. The soil must be moderately acid and good drainage is essential. If waterlogging occurs the soil will become sour and the ferns will soon die.

AS AN INDOOR PLANT. Potted ferns in the house require special care, particularly when a dehydrating atmosphere has been created by heating or air conditioning. The drying out effect can be partially offset by grouping a number of potted ferns together on a shallow tray filled with water. The pots should be raised above the water level on stones. The water in the tray will rapidly evaporate so the level should be checked and topped up regularly. Alternatively, an effective method is known as double-potting, where the fern is planted in a porous (say terracotta) pot inside a larger non-porous pot
containing a base of pebbles. In the space between the two pots pack dampened sphagnum moss and keep the moss permanently damp. Indoor ferns should be placed in a draught-free position with plenty of light but direct  sunlight through glass should be avoided as it’s likely to burn young fronds.

FERTILISERS. Great care must be exercised when using artificial fertilisers, but liquid organic fertilisers such as fish emulsions or seaweed, diluted to one-quarter normal strength are suitable.

PESTS. There are a number of pests, including snails, red spider and millipedes. Ants are particularly dangerous to ferns as they “farm” aphids, scales and mealy bugs in order to “milk” the surplus sap from these insects to feed their young by carrying them from the nest to their sucking position, and even provide protection from rain by removing them to underground positions and placing them on roots of certain weeds. When the ants collect and return the aphids to the ferns, they not only suck nourishment from the ornamental plants but introduce fungus and virus diseases. Unfortunately the fern fiddle heads are the favourite food of young emerging aphids, and damage to these destroys the complete structure.  Ants have few natural predators, but sprays and powders that destroy ants’ nests are far too powerful for delicate ferns so locate the ants’ nests and carefully treat the soil with malathion or some other weak
organophosphate, making sure the chemical does not come in contact with the fern.

Blechnum wattsii
     Blechnum wattsii
Article and photographs by AndrewWoolford
(Additional material from “Growing Ferns” by Ray Best)
Blechnum minus
       Blechnum minus

Blechnum cartilagineum                                                                               Gristle fern
Blechnum cartilagineum
Vulnerable species in Tasmania, known only from isolated north and north eastern sites, but more widespread in eastern mainland states.



see also Bracken

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