‘Prostrate Tree Fern’
The name Dicksonia lanata derives from:
Dicksonia – named in honour of James Dickson, 1738-1822, a British nurseryman.
lanata – the meaning of the name is unknown. The species was discovered by William Colenso (1811 –1899).Colenso was an avid botanist who worked closely with Kew Gardens detailing and transmitting his finding back to the country of his origin. He was also notable for the first printing of the Treaty of Waitangi.
The Maori names for this tree fern include ‘tuokura’ and ‘tuakura’ other common names include ‘Prostrate Tree Fern’, ‘Woolly Tree Fern’ and ‘Stumpy Tree Fern’ due its relative lack of height.
Dicksonia lanata is endemic to New Zealand’s North and South Islands. There are two forms of this tree fern in the wild.
A trunked form is found growing in the Kauri forests of Northland where species develop a short slender trunk measuring up to 2m x 15m (7ft x 6 inches).
The prostate form is more widespread growing on around the centre of the North Island but is uncommon is the far most southern regions of the North Island. The prostate form is also found on the South Island, growing on the west coast from Marlborough down to Franz Josef. The species grows between sea level and 700m in lowland and montane forests. In the South Island the species is rarely found growing below 250m.
Research into the two forms show only marginal molecular differences and probably constitute sub species. The prostrate form is considered much easier to cultivate.
Dicksonia lanata like many of the tree fern species of New Zealand can be considered hardy to some extent. The species has been considered to be hardy down to -6°C (20°F) but I think this is on the optimistic side and would only consider it hardy if well protected down to around -4°C (24°F).
Dicksonia lanata is an unusual but attractive species, with yellow/green fronds that are paler on the underside. The fronds measure between 75cm-2m (30 inches – 7ft). Plants will only produce a few fronds at a time; these quickly fall from the trunk once dead. The trunked form of the plant often look a bit ‘tired’ with a slender trunk and only a handful of fronds but appearances can be deceptive and this is just the way the plant has evolved.
It is best to plant Dicksonia lanata in a sheltered spot which enjoys filtered sunlight. It will enjoy a loose well drained soil with added organic matter and kept moist during hot summers. The species is not as thirsty as others and when mature can form a nice dense clump.
Before buying a trunked specimen of Dicksonia lanata make sure that it is well rooted and has croziers dormant in the crown. The trunked species is notoriously difficult to transplant and best attempted from spore. I would also recommend growing the prostate form from spore as they will only take a few years to grow into a good size plant and the plant will have acclimatised to its natural environment.
Family Name: Dicksoniaceae.
Common Names: Prostrate Tree Fern
Position: Sheltered position with Partial shade.
Soil: Humus-rich, neutral to acid soil.
Growth Rate: Slow.
Eventual spread: 4m.
Max Height: 2m or prostate depending on form.
Hardiness: Half Hardy – they are hardy down to -4°C and the foliage is hardy to -2°C.
Summer tips: Keep damp in first few years and feed monthly during growing season.