How do moth orchids grow without soil?

Moth orchids (Phalaenopsis) are epiphytic plants, meaning they grow on other objects—typically trees—for physical support rather than in the ground. Because they do not rely on soil for nutrients, they have evolved specialized adaptations to survive in the canopy.12

These orchids obtain water and nutrients from their environment through their thick roots, which are covered in a specialized, corky epidermis known as a velamen. This structure acts like a sponge, absorbing moisture from rain and water vapor in the air.23

While they do not require soil, they still need access to nutrients, which they typically derive from organic debris—such as decaying leaves—that collects on the host plant. In cultivation, this is often replicated by potting the plants in loose materials like wood chips, which provide the necessary drainage and aeration for their root systems.21