Thanks, Daisy!
I've always stuck with pine bark for bonsai and fir for orchids, but only because "we've always done it that way". I like having a bit more to go on than that. One of my orchids (Brassavola cucullata) is mounted on a piece of cork and it is a very happy little camper. It loves lots of air circulation so cork works nicely for water retention and the roots grow onto it readily.
This information will help with what I want to do with mixes for various potted plants. I appreciate the help!
