What are the considerations for orchid potting soil?

The soil used for growing orchids generally depends on the orchid variety, and broadly speaking, orchids can be divided into terrestrial orchids and epiphytic orchids. For example, Cymbidium goeringii, Cymbidium ensifolium, and Cymbidium hybridum are terrestrial orchids, so they need to be grown in loose, breathable, fertile, non-sticky, well-drained, slightly acidic soil with good physical properties; common options include fairy soil and peat soil, and you can also mix your own, or collect it from mountain forests and trees, disinfect it, and then use it. For example, Phalaenopsis, Angraecum, and Dendrobium are epiphytic orchids, and they cannot survive in ordinary soil; even loose, breathable granular soil does not let them grow well. Generally, a substrate with larger particles, excellent breathability, and good drainage is chosen, such as volcanic rock, aquarium rock, expanded clay pebbles, and sphagnum moss. Terrestrial orchid soil contains nutrients, so appropriate fertilization is enough, while epiphytic orchids need frequent watering with dilute fertilizer solution, otherwise they will suffer from nutritional deficiency and their growth will weaken.