Orchids are an unusual flowering plant in that many grow best when not planted in soil. For many types of orchids, planting the roots in sphagnum moss or other sterile growing medium and allowing the roots to pole through into the air is the best method of cultivation. Outdoor cultivation during warm seasons is not difficult.
In nature, orchids usually grow in filtered sunlight on the sides of trees, logs or other organic surfaces. Orchids do not grow in soil or in the ground. If you are fortunate enough to live in a sub-tropical to tropical climate, you can sometimes get an orchid to grow simply by wiring it in some sphagnum moss to the side of a tree. The leaves on the tree will often filter the night enough to allow for good growth.
Orchids need light, but don't do well in full sunlight. In most cases, try to hang your orchids outdoors in a place that gets between 20 and 30 percent sunlight. If the sun is unusually hot where you live, offer your orchids more shade and protection.
Orchids don't require traditional watering. If your climate is hot and humid, they may well get enough water from the air and through dew in the morning. However, in most areas you will likely need to sprinkle and mist your outdoor orchids in the morning. By sprinkling the roots and misting the whole plant, you are mimicking early morning dew. By doing this in the morning, you should have few problems with mildew caused by water standing for too long.
Fertilize your orchid once every week or two with quarter- to half-strength African violet fertilizer. Add liquid fertilizer to your spray bottle and spray the diluted fertilizer on for two consecutive days. Although orchids often don't require much fertilizer, gentle fertilization can help maintain plant health.
Unless you live in a climate where your orchids will winter over, hang your orchid baskets under a tree or in another sheltered area. Try to keep the roots away from tree trunks or wood posts to avoid having the roots attach themselves to the surface. If you live in a warm climate where your plants will survive the winter, simply wire the orchid in sphagnum moss to a tree trunk or post and allow the roots to attach themselves. After several months, you should be able to cut the wire and grow your orchids much like they would grow naturally.