Q. What is a Dicksonia antarctica?
A. It’s a rhizomatous, evergreen perennial from Australia that resembles a tree with massive fern fronds. Its more commonly called the Australian, Tasmanian or Woolly Tree Fern. It has a thick, hairy, erect rhizome, like a tree trunk and large, dark green fern fronds arising from the growing point at the ‘crown’ of the rhizome.

Q. It looks like a tree stump at the nursery – why all the fuss?
A. When Dicksonia antartica arrive in the UK they will have been sawn off at ground level and all fronds removed. They do indeed resemble a very expensive tree stump. Within weeks they will begin to produce fronds and once planted they will develop a root system. Within 6 months to a year they will be firmly rooted into the soil.

Q. Is it hardy?
A. Despite the severe winter of 2009/10 in the UK, losses of this species of tree fern were minimal. Unfortunately, many other species of tree fern proved not to be able to withstand a particularly harsh UK winter and were lost in gardens all over the country.

Q. How fast and how big will it grow?
A. It’s a very slow growing plant, approximately 1.5cm of growth of ‘trunk’ per year. However, frond length is not dependant on trunk height and specimens with just 60cm of trunk may produce fronds of 2 or 3 metres in length. Mature specimens, many decades in age can reach 12m or more. Dicksonia antarctica, several centuries old exist in the wild.

Q. How deep should I plant it?
A. As Tree Ferns are sold per foot of trunk, it’s a shame, and a waste of money to bury an unnecessary amount of trunk underground. Between 4 and 12cm is adequate. Larger specimens may need staking for the first year, until their roots have formed. After a year the stake may be removed and the tree fern will be self-supporting.

Q. I’ve been told that Tree Ferns don’t have roots and don’t need planting. As long as you give them lots of food and water they can survive standing on a concrete patio. Is this true?
A. In our experience not true. Tree ferns absorb water and nutrients via their roots as well as from the crown, and if left unplanted, tend to deteriorate after a couple of years.

Q. Will it grow in a pot?
A. Almost any plant can be grown successfully in a pot and provided it is supplied with adequate food and water and re-potted when required, it makes a fantastic pot plant. We recommend planting and keeping a bare rooted specimen in a small pot until it has produced roots. It may then be planted into a larger pot. Over-potting bare rooted plants can lead to failure, as the roots tend to rot as fast as they are produced. One cautionary note about growing Dicksonia Antarctica in a pot though – use a very heavy pot with a low centre of gravity as tree ferns are top heavy and pot, tree fern and all can be toppled in strong gusts of wind.

Q. Does it need sun or shade?
A. It’s a woodland plant and prefers shade. It’s possible to grow in full sun but the fronds may be shorter and there is always the danger that the trunk will become dry. Don’t plant in full sun unless you intend to soak it daily in the summer.

Q. How much food and water should I give it?
A. Tree ferns love cool, moist conditions and are therefore suitable for most UK gardens. They grow particularly well in Ireland. Debate still rages about the correct method of watering – whether the crown or trunk should be watered. We recommend watering both liberally, daily in summer. Either spray with a hose or use drippers, connected to a watering system to slowly drip several litres of water into the crown. We also recommend feeding weekly during the growing season – again into the crown.

Q. Should I protect it in winter?
A. The recommendation for winter protection used to be a handful of straw or leaves, stuffed into the crown before the onset of frost. However, this has been revised after winter 2010/11. In anticipation of another destructive winter, we recommend using a 3ft long fleece bag pulled over the top 2ft of tree fern trunk (you will have to cut the fronds off). This should be generously stuffed with straw, including the 1ft of fleece bag above the crown. Over this should be placed a piece of plastic sheet, securely tied, to keep out rain. This should keep your tree fern snug during the harshest winter months.

Q. I have a greenhouse. Should I grow it in a pot so I can place it under glass in winter?
A. In our experience this isn’t a good idea. Dicksonia Antarctica are far more likely to succumb to drying out than cold and frost. Best to wrap in situ.

Q. When do I unwrap it?
A. Usually around April, although in mild springs the fronds may have begun to emerge from the crown and pushed out the protection anyway.

Q. I’ve unwrapped my tree fern but it hasn’t produced any fronds. Is it dead?
A. Don’t be too impatient. Sometimes it can be well into summer before tree ferns produce fronds, especially if the spring is very cool. If it still hasn’t produced fronds by mid-summer, inspect the crown. A firm crown with protruding knuckles means that the fronds are in position and ready to go! Keep watering liberally. Plants are amazing things and we never stop learning. Last year we had a 6ft Dicksonia antartica in the garden that didn’t produce any fronds in a season, a sure sign we believed, that it had died over winter. Lo and behold, this year it produced fronds. We hadn’t dug it up and disposed of it because we planned to grow epiphytes on the trunk – phew! The moral of this is obviously don’t be too quick to condemn a tree fern that’s slow to produce fronds – it may just be taking a year off.

Q. Fronds are emerging but are small, weak and turning black. What’s going wrong?
A. Don’t panic. At the beginning of the season, if we experience late frosts the fronds at the top of the crown can be damaged and blackened. These will emerge, as described and can be removed. New, healthy fronds should follow shortly after.

Q. I’m worried about conservation. Isn’t it irresponsible to import these plants?
A. Few countries in the world are more concerned with conservation than Australia, but ‘progress’ being as it is, land is required, and just as in the UK, this usually involves land clearance. Tree Ferns were viewed as worthless and would have been destroyed until recently. A market has been discovered for them as ornamental plants across the globe. All tree ferns entering the UK are harvested under license and have a certificate with a unique number so you can enjoy one of these incredible plants without a guilty conscience.