| I have to stick up for sphag; I have all my phals in it and they love it. It depends on your watering habits. I have a tendency to forget about my phals and in the winter they are watered about every 10-14 days. However if you think that you'll want to fuss with them more, then a faster drying media such as bark might work better for you.
And to answer your question about pot depth. I don't put my phals in particularly shallow or deep pots- just a run of the mill orchid pot seems to suit them fine. |