Many years ago as an Apprentice for the Parks Department, I was moved around to learn different jobs; one of these was in the nursery. My foreman grew a lot of plants for the Municipal buildings and one of his loves was tree ferns. I too became interested in them as they fascinated me; they were to me like looking at the "Dawn of Time." He soon noticed my interest so I was given the job of looking after them, a job I was most happy to do. To me, seeing the new spring leaves typically expand by the unrolling of a tight spiral called a crozier, was an exciting moment, and still is. It's sheer wonderment as the new life begins. On the left is one of mine in the summer and the other is in the snow and ice, neither of which is what I recommend. For they prefer dappled shade.
This wondrous plant causes a lot of debate; some say it has no roots and others claim it has, Wikipedia says the "trunk" of this fern is merely the decaying remains of earlier growth of the plant and forms a medium through which the roots grow. The trunk is usually solitary, without runners, but may produce offsets. They can be cut down and, if they are kept moist, the top portions can be replanted and will form new roots. The stump, however, will not regenerate since it is dead organic matter. In nature, the fibrous trunks are hosts for a range of epiphytic plants including other ferns and mosses. On the left is the same plant after the thaw and on the right, even after doing nothing, the new life started.
The debate on how to keep them over winter is equally heated. The old way was to get some chicken wire, fill it full of hay and put it over the top, thereby protecting the "crown". The crown can be seen above in the centre of the picture on the right! I wrap mine around the trunk, or stipe with Horticultural felt, then with a massive old sock I fill it with hay and protect the crown with that, and it works for me. They are said to be safe to minus 10C or 14F, but as they are evergreen I would not trust them at that without protection. Mine have suffered -26F and survived. In severe weather they will lose their leaves. However many people keep them in containers and bring them into a cold conservatory or greenhouse to over winter. Here is one that has lost its leaves and now has new croziers.
They prefer shade or dappled sun and too much or too little water will kill them. If it is hot in summer, I water mine three times a day in the crown. Although mine are surrounded by river gravel which when wet keeps the humidity up, I also put organic matter around the base as that helps as well. They are very slow growing, but can reach 45 feet. In cultivation they normally get to about 15-20 feet after a very long time. Although there are other tree ferns, Dicksonia is the most common in cultivation, especially in the UK. Here is one of mine the other day.
They originate from south Australia and Tasmania, and as mentioned are suffering due to habitat loss. Due to their slow growth they are normally sold by the foot, and are very expensive. However they can be grown from spores which are available on the internet and full instructions are also easily available. Please do not take any notice of bits of paper attached to plants saying Certificate, that is just a state licence to allow the loggers to take them from the wild. Mine are all from spores, grown in the nursery I used to work in. A view from the side, and from the top taken today.
It is now August and to my disbelief there are still new Croziers (new fronds), coming out. Here is a new one and a macro of the same one!
I cannot get over the fact that it is nearly September, and this one plant is still shooting out new fronds.
My little tree fern is now producing croziers and the big one has gone mad.
Some more shots this year 2013 after the Hurricane that hit us. Does not this tree fern look stunning?
This year 2014! After lots of damage by building work, they come alive again.
Now one of her offspring on the left, with a new crozier. Sorry but I adore them.
They now have a new botanical name which is;