C. australis is commonly known as the Rough Tree Fern due to the presence of adventitious roots, tubercles (knobbly bits) and masses of hair-like scales on its 'trunk'. The 'trunk' like structure on a tree-fern is actually a greatly enlarged rhizome! The horticultural appeal of C. australis is not only due to its beautiful looks but also because it is an extremely hardy species, even capable of tolerating direct sun when the roots are wet. It is also a robust tub plant and is unusual in that it is tolerant of salty winds. C. australis is thus a popular, cold-hardy tree-fern, adaptable to a variety of climates and soils.
Tree-ferns grow best in high humidity and high soil moisture conditions. It is therefore important to use good-quality mulches and to top them up regularly as this will not only keep the soil moist but also provide nutrients to the shallow root system. Tree-ferns usually respond well to organic fertilizers and well-rotted animal manures.
C. australis has a crown of similar size to C. cooperi
but the frond bases are covered in narrow dark brown scales and are quite prickly to the touch.