Chapters

Caring for Dicksonia
Planting a tree fern - Video Tip
Winter Protection - Video Tip
Winter Protection
Spring Tidying - Video Tip
Gymnosperms and angiosperms - Video Tip
Further Reading
Plants

Dicksonia antartica - Care Guide

Caring for Dicksonia

D. antarctica is the only Australian or New Zealand tree fern which is genuinely hardy in all but the coldest UK gardens. A run of mild winters may have tempted gardeners in the recent past to try D. fibrosa, D. squarossa and a range of trunk forming cyatheas. B&Q were selling them by the thousand a few years ago. However, after the winter of 2012 especially, gardeners have learnt the hard way that D. antarctica is the only survivor in all but the most mild coastal gardens in the south west of England.

Dicksonia antarctica

Dicksonia fibrosa

Trunks of D. antarctica arrived at Falmouth Docks in the 1840s and 1850s. The huge fibrous trunks were used as ballast in the holds of ships to prevent cargoes moving about. At the dockside the bare trunks were seen to be growing fronds and, from there, it was a small step to them arriving in many Cornish gardens. At Caerhays dicksonia thrive in two damp and sheltered quarries. There are 30 or more trunked plants in each quarry and their spores reproduce readily in dampish shady spots all over the garden as well as up and over the stone sides of the quarries. Old plants with trunks of 15-20ft tall eventually fall over but their crowns reroot and grow away again.

The extraordinary thing about tree fern ‘trunks’ is that the pithy trunk is shrouded in a mat of aerial roots. This means that you can take a chainsaw to a tree fern trunk and cut it in half at any height. The half with the crown can be plonked in the ground wherever and will speedily root out and grow away.

In our climate D. antarctica can be grown as a freestanding plant virtually wherever you like in sun or, preferably, partial to full shade. Elsewhere in the UK a damp, sheltered and fully shaded spot is the best bet. These plants grow well in the damp near water. The fronds can be 10ft long and older fronds die off and hang over the trunk. The temptation is to remove them as being unsightly but they perform a useful job in retaining moisture around the aerial roots all over the stem.

Dicksonia antarctica

Dicksonia crown

In cold and windy winters the fronds may get frosted and damaged by wind. In a mature plant a whole set of fronds may be killed off. This will not prevent new fronds emerging in April and May from the crown providing you have protected the crown with leaves, straw or shredded paper tied in place. In March you have only to feel into the crown to discover if the fronds are there. If you forget to cover your crown and it dies completely you can always insert a young plant with some soil into the crown. With care and watering it will grow away and take over the old trunk.

Protecting your tree fern from frost is shown in the attached photographs but this is unnecessary in milder parts of the country.