Dicksonia antarctica tree ferns, in various sizes from 30 cm to 2m of trunk.
Family Dicksoniaceae
Originating from S.E. Australia and Tasmania

• Received the Royal Horticultural Society’s Award of Garden Merit.
• One of the most iconic exotic woodland plants with huge lacy fronds atop a thick fibrous trunk.
• Impressive flushes of many thick, tightly curled new leaves unfurl in spring.
• Easy to grow with plenty of moisture in dappled shade of full sun

The Characteristics of Dicksonia antarctica tree ferns.

The ultimate jungle-style fern with abundant huge leaves up to 1.8m long. It is also refined and elegant enough to grace English, oriental, or woodland style gardens, being less ostentatiously exotic than plants such as bananas or cannas. New croziers (furled fronds) emerge in the spring with a mysterious beauty of their own, looking prehistoric and fecund. As many as 30 or more can be produced in one spectacular flush, looking like clenched knuckles as they emerge from the top of the trunk. They soon begin to unfurl, arching gracefully to reveal the beautiful geometry of their leaves’ arrangement. The vibrant, fresh green of the new leaves and the lacy complexity of their feather-like structure is one of the highlights of spring. As they mature their colour darkens to rich green, and the intricate, bipinnate structure of the leaflets attain their full width in a feather-like arrangement on each side of the rachis (central stem), forming a frond up to 70cm wide. 

The trunks of Dicksonia antarctica tree ferns consist of a mass of compressed fibrous roots, that in the humid temperate forests of their native Tasmania are capable of absorbing water from the atmosphere. Whilst the trunk appears to be dried out and no longer alive, we have been surprised to see them produce new roots from half way up the trunk when they have sensed the close proximity of water. These new roots have grown into ponds and streams, where specimens have been planted leaning out over water. The dark brown, fibrous, shaggy trunk adds to the ancient appearance of the plant, and its availability in different heights up to 2m tall, and sometimes up to 30cm thick, sometimes with slight curves to the trunk (ideal for leaning out over water), gives gardeners a wide range of characters to choose from.

The ‘Tasmanian Tree Fern’ grows very slowly compared to most other species of garden plants. A well established plant, given plenty of water, can grow 5cm of trunk a year and produce several flushes of leaves during the season, depending on the shelter and humidity of its location, (see more in our planting and care section below). Fresh, newly matured fronds have an upright poise which may last for many weeks before they gradually recline to a horizontal and then to pendulous position near the end of the season. On a strongly growing plant that produces more than one flush during a season it is possible to see leaves at all angles of repose, making a full and generous crown. Fully hanging leaves can remain green during winter, and only turn brown in severe frost. Some gardeners prefer the wild look of a skirt of dead leaves hanging from their Dicksonia’s, leaving them on the plant until they fall after many years. Tidy gardeners remove the previous year’s fronds annually.  

For an in depth description and account of the largest specimens growing in the UK visit
https://www.treesandshrubsonline.org/articles/dicksonia/dicksonia-antarctica/

The History and Origins of Dicksonia antarctica.

Growing in moist gullies in forest microclimates and at altitude in misty, cloud shrouded, mountainous regions of Southern Australia and Tasmania, this impressive tree fern forms large colonies, growing trunks up to 4m tall. Taller specimens sometimes fall over and continue growing from the crown, reestablishing a vertical trunk, often with new plants setting spores into the fallen section, which provides the perfect moist, fibrous environment for the spores to grow through their primitive life cycle. As such, this species establishes its own woodland environment of dense communities, growing on the forest floor and from wet rock faces; anywhere the slime or moss/lichen-like gametophyte (its first stage of growth from a dispersed spore) can find a foothold, before developing into a sporophyte plantlet, when it starts to resemble a fern.

Many plants were introduced to the UK during the Victorian era due to the influx of species from the colonies. The craze of plant collecting took hold and many of the house plants and other exotics we know well today became available for the first time in this era. Dicksonia antarctica found its way into gardens via a more utilitarian route however; the trunks were so abundant in Australia and Tasmania that they were used as ballast in the cargo holds of ships to stop goods from moving during the long voyage. After they were unloaded and stacked at the docks it was noted that they were shooting new leaves from the tops of the trunks. From there they  became one of the most popular Victorian garden and conservatory plants.

Today this exceptional fern is made available to gardeners in Europe due to the clearance of their habitat for development in Tasmania, where their removal is strictly controlled. All our plants have a license tag attached to their trunks, issued by the Tasmanian authorities to verify that they have been responsibly harvested. Such is the physiology of the plant, they can be sawn off at any point in the trunk below 30cm from the crown (where the growing tip is located), and the plant will re-root into the soil of its new location, from the base where it was cut. New fronds will grow, regardless of whether it has re-rooted. 

Planting suggestions for Dicksonia antarctica tree ferns.

Selecting your tree fern presents you with a range of options, in height, shape and thickness of trunk. Each size has its own range of qualities you can use in planting compositions.

One of the most impressive ways to view a Dicksonia is looking down into its crown, where its full spread and radial, shuttlecock-like habit can be appreciated. Smaller sizes of trunk allow this, up to about 1m high, when viewing the plant when standing. Unless you have a high vantage point in your garden from which to look down on them, you will miss this aspect if you plant specimens with taller trunks. Due to their slow growth rate it is possible to use juvenile plants without trunks, or short trunked ones below medium sized trees such as Acer palmatum ‘Atropurpureum’, Koelreuteria Panicutlata, or Acer x conspicuum ‘Red Flamingo’. With harsh winters in mind, when Dicksonias may lose their leaves, evergreen species are a good choice aesthetically. Species such as Ilex perado subps. platyphylla, Trochodendron aralioides and Eucalyptus gregsoniana will not only provide a winter foliage backdrop, or canopy, but provide a microclimate for the tree fern. As Dicksonias slowly develop a trunk, the canopy of trees planted above them can be pruned to give space to the tree ferns crown. Due to Dicksonias’ low and wide spreading crown underplanting of smaller specimens is not possible.   

Dicksonia antarctica tree ferns with more than 1m of trunk make a great architectural statement, with more of a vertical presence. This is even more apparent when the emerging fronds are in their upright stage, adding another 1.5m to the overall height of the plant. Taller plants, with their prehistoric looking trunks add a primeval feel to gardens and this can be enhanced with low underplanting, allowing for the lower, hanging stage of the fronds’ life cycle. Varieties such as Bergenia ‘Autumn Magic’, Epimedium x warleyense, Epimedium x rubrum, and of course many lower growing ferns such as Blechnum spicant, Polystichum setiferum ‘Proliferum‘, and Dryopteris affinis ‘Crispa Gracilis Congesta’ will create a suitably wild and ancient forest style to complement tree ferns.

The tallest tree ferns we offer with 2m of trunk can be underplanted with low growing evergreen species that will compensate for the lack of Dicksonia leaves during harsh winters. Varieties such as Pittosporum tenuifolium ‘Tom thumb’, Pittosporum tenuifolium ‘County Park’ and Pittosporum tobira ‘Nanum’ will create a soft mound-forming organic spread beneath them, contrasting with their upright character, whereas Astelia ‘Red Shadow‘, Astelia nervosa ‘Westland’ and Phormium ‘Jester’ will make a spiky and colourful composition below them.      

Planting and Caring for Dicksonia antarctica.

We recommend planting Dicksonia antarctica with a minimum of 8-10cm buried in the ground for plants with 30cm of trunk. For 60cm to 90cm of trunk up to 20-30cm should be buried, for taller trunks 30-40cm buried is ideal. Tree ferns will root and establish faster, the greater the amount of trunk is buried, but it depends on how much of the height the owners of the newly acquired plant are prepared to sacrifice for the sake of the plant’s establishment. There is also the question of stability; a well watered tree fern trunk can weigh a considerable amount, and with a large crown of leaves atop it can catch the wind, so if less trunk is buried, support may need to be provided, especially so if planted at an angle. Some gardeners have chosen to stand their tree ferns on the ground, without planting any of the trunk into it, supporting the trunk while it roots out from the bottom of it, to maximise the visible height of their Dicksonia. It will take longer for the plant to establish and extra vigilance is required to keep it adequately watered, therefore we do not recommend this method of planting, although the fact that it is able to root in this way demonstrates the robust nature of Dicksonia antarctica, having arrived in the UK as just a trunk with no foliage or roots.

Watering Dicksonia antarctica tree ferns, the ‘Man Fern’.

Adequate watering of this magnificent tree fern is crucial, as evidenced by the locations of some of the most vigorously growing and healthy specimens in the UK, where there is higher rainfall, such as Cornwall and Ireland. While a newly planted specimen is establishing, regular soaking of the trunk from the top of the plant is necessary, preferably into the top of the crown. One of the best ways to achieve this is to place irrigation drippers into the growing tip of the plant, running the 5mm pipes up the least visible side of the trunk and placing one or more drippers into crown. This method ensures a slow and steady supply of water, allowing the trunk to better absorb the water and also fertiliser, if you can add it to the water supply. A general purpose liquid feed can also be applied to the Dicksonia crown using a watering can, poured slowly into it. Plants that are fed and watered in this way not only establish faster but grow larger leaves in several flushes each season, and are able to grow in full sun. A woodland microclimate also has a marked effect on the leaf size, the number of green healthy leaves in the crown and their resistance to cold. The ambient humidity found in woodland environments mimics that of their native climate and has been a key factor in some of the healthiest plants we have seen in the UK.

When Dicksonias do not receive adequate water, and have their leaves removed too early their crowns can ‘close up’, leaving an ever tighter aperture at the growing tip, which produces smaller leaves each season. We recommend leaving the dead leaves hanging on the plant until the new season’s fronds have unfurled. Their weight and downwards curvature at their base helps to keep the crown aperture open.

Winter Protection.

Winter protection for Dicksonia antarctica tree ferns is only necessary when the temperature drops below -6 degrees for more than one or two nights. Temperatures below freezing may cause the fronds to brown, but this is natural superficial ‘damage’ and does not affect the health of the plant. The top 40cm of the crown can be protected by first pushing a handful or two of straw lightly into the crown and then tying up the fronds around it, then two or three layers of horticultural fleece fabric can be wrapped around it and tied so that the crown and straw is enclosed, leaving the tips of the tied, now upright fronds exposed. This ensures that the crown (the growing tip of the plant) is insulated. Plastic materials should be avoided unless used for short durations and then removed as soon as temperatures rise; if left on the plant for an extended period moisture can gather and rot the crown, being as damaging as the cold. Protection of the trunk below the top 40cm is only necessary in extreme winters, especially in wet conditions when it is soaked, sustained cold for periods of 3 nights or more, below -8, especially when temperatures do not rise above 0 degrees during the day. In such harsh winters it may be required to wrap the entire trunk with fleece enclosing straw against it.              

Mature height and spread after many years 4m x 4m