‘Bristly Tree Fern’
The name Dicksonia youngiae derives from:
Dicksonia – named in honour of James Dickson, 1738-1822, a British nurseryman.
youngiae – the meaning of the name is unknown.
The common name for Dicksonia youngiae is the Bristly tree fern due the frond bases or ‘stipes’ being covered in coarse hairs.
Dicksonia youngiae is endemic to Australia and can be found growing in subtropical rainforests of Queensland and Northern New South Wales. The fern has become rarer over the last few decades due to clearance of its natural habitat. The fern can still be found in restricted occurrences, including in Lamington National Park and the Atherton Tablelands. Dicksonia youngiae can be found at altitudes near sea level and up to 1200m in the rain forests.
The trunk of Dicksonia youngiae can grow up to 5m (16ft) and around 20cm (8″) in diameter. The species is similar in appearance to Dicksonia squarossa, both being clump forming and will often send up a new growth point from the base, to form thickets of plants. The species is relatively fast growing capable of adding 10cm of growth to its trunk in a growing season. However when trunks get above 3m they can start to become unstable and tople over, if the trunk is in contact with the ground a new plantlet will often grow from the fallen trunk.
Dicksonia youngiae is an attractive fern, the trunk and stipe basis are covered in reddish brown hairs or bristles. The fronds are glossy green with a coarse texture. The fronds measure up to 3m (10 feet) in length and 45cm (18″) in width.
Dicksonia youngiae is not fully hardy and I would be very sceptical if it would tolerate more than a few degrees of frost. Some growers however believe the species to be more cold hardy than Dicksonia squarossa. My theory would be only testing it if you can afford to lose it!
Dicksonia youngiae is sometimes confused with Dicksonia herbertii but there are several distinguishing features, the stipe hairs on Dicksonia herbertii are larger and extend right up the stipe bases and around the top of the trunk. Also Dicksonia herbertii is not clump forming and does not throw up new suckers from around the base of its trunk. Finally the fronds of Dicksonia herbertii are a duller green.
Dicksonia youngiae needs to be grown in a spot sheltered from wind with high humidity and good sunlight. The main way to keep this species happy is a good supply of water and still damp conditions, not easy to create unless they are naturally occurring. The species will do best in a loose well drained soil with added organic matter.
Family Name: Dicksoniaceae.
Common Names: Bristly Tree Fern
Position: Sheltered from winds with high humidity.
Soil: Humus-rich, neutral to acid soil.
Growth Rate: Fast.
Eventual spread: 6m.
Max Height: 5m.
Hardiness: Half Hardy – they are hardy down to -1°C.
Summer tips: Keep constantly damp and feed twice monthly during growing season.