It's a nobile dendrobium. Very hardy. In Cairns you can literally just tie them to a palm tree and they will grow.
They like bright light, so full morning sun is good with a bit of light shade in the afternoon.

Position the log where you want, put some heavy sstones in the bottom to maintain stability and ensure drainage then just pop the plant in and pack orchid mix around to hold it steady. You could even just pack coconut husks around it so make sure it doesnt wobble. It only has to hold it until the roots attach to the wood.

Just to add to the above, it is indeed a nobile type Dendrobium and it needs two seasons a year just as nature provides in Cairns. The wet and the dry!
During the wet it will grow a new cane/pseudobulb from a growth eye at the base of the plant and then the plant will rest during the dry and flower just before the onset of the next wet season.
Do not fertilize or water the plant overmuch during the dry because then it might grow baby plants from the nodes along the canes rather than flower.
Perhaps it might do a little better up on the tablelands.

This post was edited by arthurm on Wed, Sep 24, 14 at 4:07

All of the above. Bore several large holes in the log. 1/2 inch. In orchids you can't have too much drainage. When potting orchids they must be on top of the medium not in it. In pots there can be applied a rhizome clip. It fits tight on the edge of the pot and extends over the plant at the base to hold it in place. This is important for long life. It might be a little tricky being your first and a customized clip will be needed due to the log.

Perhaps 2 small drilled holes slightly above the rocks. Then thread a stiff wire through. If you were nearby I'd come over and I'll fix it for you but you are soooo far away.

You might need help for the first one.

Good luck.

what is the orchid growing in? in Cairns i saw orchids growing ina local volcanic rock. is that it? you could just fill the log with big volcanic rocks and wedge the orchid in tight with them, then sprinkle some smaller grade medium over the roots.

if this sounds like too much, lash it to a tree :)

Here is a link that might be useful: orchids on trees

Nobile den

Here is a link that might be useful: {{gwi:195687}}