Sphagnum moss is an ideal planting medium for most orchids because it can hold onto moisture but is also loose, airy and free draining so it will not suffocate the orchid roots. Sphagnum moss can be used as the sole potting material for epiphytic orchids. It can also be mixed into your proprietary blend of potting medium for terrestrial orchids along with bark, soil, perlite and charcoal.
Wet the sphagnum moss with clean, tepid water to make it pliable and easy to work with.
Slide the orchid out of its old pot and planting medium and carefully brush the old medium from between the roots. Wet the roots under tepid running water to rinse off old medium and hydrate them.
Fill the new orchid pot one quarter of the way full with chunks of wet sphagnum moss. Set the orchid in the pot and spread the roots evenly without breaking or straining them.
Gently push bits of wet sphagnum moss into and around the table of roots using your fingers or the eraser end of a pencil to fill in around the roots so that they are touching the sphagnum medium but are not compacted in it.
Place the orchid back in its usual growing location watering weekly and fertilizing monthly as usual.