If it helps, I also grow mine in potting soil.
-Pat
You folks have to remember Pat lives in Florida. Almost any orchid will grow there, even in soil . I think the northernmost members (Canada and Michigan/Minnesota) might want to grow in peat (not sphagnum) mixed with local soil to bring pH up to near 7.0. This is what they would grow in here. Rotten logs, etc. I plan to venture into these this summer.