Some plants root better in one media than others, and sphagnum moss offers long fibers that hold moisture without staying too wet. Another way to say this is that some plants need better air circulation around cut surfaces to prevent rot and encourage rooting. Sphagnum is the go-to medium for creating air layers. Too often overlooked, air layering can rescue a corn plant that has leaves only at the top of a tall caned stem. I like to use air layering on woody plants and fruit trees that have stems between ¼ and 2/3 inch in diameter. I did not know that sphagnum moss is a wise choice for rooting terrestrial orchids until I attended an Orchid Society meeting years ago. Since then I’ve adapted the member’s method to start many new orchids from stems and broken joints. It could not be simpler: wet the moss and squeeze it out so it is damp but not dripping and fill a plastic pot with it without tamping it down. Make a fresh cut on the orchid stem, dip it into fresh Hormex, and slip it into the sphagnum. Water lightly and consistently and look for new roots in a month.