The Best Medium for Moth Orchids

Phaleanopsis Habitat

• Phaleanopsis are native to tropical Asia. They are called moth orchids because of the flat flowers that resemble moths. These plants need humidity but not wet roots. The roots have to have access to moist air, but they can be killed if they are sitting in water or soggy soils. Chunky or porous media are the best choices to mimic the natural growing conditions of the orchid in warm humid forests. Potting soil or heavy compost will retain too much water and hold fungal spores that thrive in the conditions the orchid requires.

Materials

• There are many appropriate materials to make a moth orchid medium. They can be used alone or in combination with each other. Bark is almost always a component of orchid medium. Fir bark is light and porous and readily available. Sphagnum moss and pumice mixed with polystyrene and foam fill out the remainder of an orchid mixture. Moth orchids require a medium mix with smaller bark chunks. You can also plant the orchid in peat moss or other well-draining organic material.

Watering and Humidity

• Moth orchids require humidity of at least 50 percent. This might cause the grower to think the plant needs constant moisture, but that is not the case. The orchid should be watered completely then the media allowed to dry out. This prevents fungal issues and root rot. The media should be the only part watered. If water touches the leaves, they will discolor. Orchid media provide the structure the roots need to be kept out of standing water. When making your own mixture, use two parts of bark and one part each of an organic and an inorganic additive.

Re-potting a Moth Orchid

• Moth orchids need to be re-potted when the medium is mushy and no longer drains. The bark will break down over time and can become more like a sponge than a freely-draining medium. Remove the orchid from the pot and dump out the old medium. Wash and sterilize the pot. Check the roots for any damage and prune off discolored or mushy growth. Wet the new bark mixture with boiling water and allow it to cool then drain it. Put the orchid in the pot and push the bark mixture around it.