Hi kindra, I've found that oncidium will grow on mostly anything providing that the media is relatively free draining. Slabs, tree trunks etc all work fine. At the moment I have a big bunch of the stuff growing around the base of a potted plumeria with 4 spikes in flower and just for kicks I threw a couple of bulbs inside a cement block in mostly full sun with no media other than the block and the dirt it sits on. The older growth suffered but now it has new bulbs which are doing fine.
I guess my point is, is to be creative and experiment. Never know KindraG, you may be the next 'trend-setter' on OB!
Interesting. But I have to be able to bring in for january/february months lows in teens!!! So cement block wont work lol!!! But thank you. Its woeking great thus far!
I have a paph, phrag, onc, milt and reed stemmed epi all in s/h in lava rock. All of them love it. I find that it wicks better than clay pellets. I use small pieces and flush them with clear water about once a week or as needed, then add a little diluted fertilizer according to what the plant prefers. I also mist the surface, especially for those that have the fan on them.