They should be allowed to dry out slightly between waterings so air can circulate between the epiphytic roots. Orchids in medium-sized pots generally need watering only once a week. But you may have to experiment with different types of potting media to find the type that is best under your conditions. Potting an orchid in Photo of potting medium, such as bark chunks, which helps create an optimum microenvironment for orchid delivery roots soil or letting it sit in a a water-logged pot will kill it, since a lack of oxygen will cause the roots to suffocate and rot. Indoors this can be accomplished by growing the orchid in a pot filled with chips of bark, stones, tree fern fiber or some other loosely packed material that allows the roots to be well-aerated and through which water can drain quickly.