Orchids are air plants, they don’t grow in soil, so you wrap their long, fat roots with a handful of moss and tie them tightly around a tree trunk. Over the next several months the roots will grow up against the trunk and secure the orchids in place. Once it’s settled you don’t even need to water it anymore, it’ll be able to harvest enough from the air (assuming you live someplace humid, of course) Not my photo, but illustrates::