The Rough Tree Fern ( Cyathea australis ) is as the name suggests native to Australia. This species is generally found growing along the east coast of from as high as Rockhampton to as low as Tasmania. It is cold tolerant and although prefers a part shaded location, will also grow happily in a full sun location.
Cyathea australis is a tree fern and can get to heights of around 10 metres tall in their natural mountainous rainforest habitat. The Rough Tree Fern can not be grown from trunk cut off’s like many other ferns, it can only be propagated by spores. If you see a fern trunk labelled as a Rough Tree Fern for sale in a nursery; it will be a different species and incorrectly labelled, as the Cyathea australis can not be grown from trunk cuttings.
Suitable for Cold to Tropical Climates. Live in a cool climate but looking for ferns that will grow in your zone and give that tropical appeal? Here’s another cold tolerant fern species – Ostrich Fern.
Growth
The trunk of the Rough Tree Fern grows on average to 7-10 metres tall and a width of 30 cm’s. Its beautiful large fronds can get to lengths of 3-4 metres as a mature tree, which can give it a massive spread of 7-8 metres. Cyathea australis gets the common name ‘Rough’ from the rough nodules and furry scales that grow on its frond stalks, these features make this species easily recognisable from other fern species.
Although it is cold tolerant down to -7°C, frost can damage young fronds. In cooler regions it is best to plant these in an area where they will be protected from frosty cold winds; as they would by other trees in their natural habitat. Mulching around the base or using river stones will help keep humidity around the plant for optimum growth.
The Rough Tree Fern is suitable for growing in containers and will give a gorgeous rainforest feel to any garden.
FAMILY:
Cyatheaceae
CLIMATE:
Cold to Sub-Tropical
TEMPERATURE RANGE:
-7 to 36°C / 20 to 97°F
SOIL TYPE:
Moist but not soggy soils, tolerant of sandy loam to clay soils.
LOCATION:
Full Shade to Full Sun
HEIGHT:
Up to 10 metres (32 feet)
WIDTH:
Up to 8 metres (26 feet)
pH:
6.0-7.0
GROWTH TYPE:
Evergreen
WATER REQUIREMENTS:
Medium.
POLLINATION:
Spores form on the underside of the fronds, which have both male and female organisms present.
MATURITY:
2-5 years
GERMINATION RATES:
70-80%
GERMINATION TIME:
Germination process will usually begin around 2-6 weeks, however it may be many months before they start to look like little ferns.
SEEDS PER GRAM:
Too many to count – well into the hundreds of thousands.
MEDICINAL QUALITIES:
No
WEED POTENTIAL:
No
EDIBLE:
No
SPORE STORAGE & VIABILITY:
Cold storage at 4°C (fridge) – 1 year
FACTS ABOUT CYATHEA AUSTRALIS (Rough Tree Fern)
Cyathea australis, although not tolerant of salty soils, copes well with salty winds in coastal areas.
This species is important ecologically in Australia because it provides a home to one of our native bees. These bees are useful pollinators for many of our native species.
Cyathea australis is also has a synonym of Alsophila australis.