I have been growing tree ferns for 10 years plus now and all I have given them in that time is Chicken poo pellets(when I can remember) and they seem as happy as Larry,you don't want to over feed tree ferns.
I was also told you could use chopped up banana peel in the crowns, they get some slow release nutrients from this, as they would from detritus falling into the crown in the wild, and the remnants of this will be ejected with the next flush of fronds.
They do like a good watering, but don't seem to suffer if it is not done on daily basis over the summer.
Newly bought tree ferns trunks can be incredibly dry, I have just bought three trunks to replace some dead cyathea , I placed them crown first into a dustbin full of rainwater for around half an hour, and they bubbled away like a jacuzzi.
Don't bury them too deep, just deep enough to ensure they are stable, I buried a 9 footer about a foot deep when I planted it and heaped soil up around its base and although it did fall down once just after I had planted it and given it a good watering, missing me my inches
![Ahh! :ahhh!:](./images/smilies/icon_e_surprised.gif)
, it has remained standing for nine years to date.
Dicksonia antarctica are as tough as old boots, and they are stunning to look at.