Tropical orchids are no more difficult to grow than other plants, but because most of them are epiphytes (tree dwelling plants) their culture is different from that of other types of plants. Once you learn what rules apply to most orchids their care becomes much easier. British orchid growers failed in the early 1800's when they attempted to grow tropical orchids under dark, hot, and steamy conditions. They succeeded only when they realized that most tropical orchids grew at higher, cooler elevations and in the upper branches of trees where they got considerable light and perfect drainage.
In the greenhouse, most orchids require some shading to prevent the leaves from overheating. In the home, however, orchids need the maximum light available. South facing windows are the first choice, followed by west and east. Artificial lighting will be needed if you do not have good sunlight exposure. Placing them outside under the shade of tall trees during the summer months is very beneficial. Do not place them in full sun, however, or the leaves will burn. Also, do not place the plants on the ground, for insects and slugs (snails) can enter the pots and damage the plants. Pot hangers can be used to suspend the plants from tree branches, chains, or other structures.
In the home, placing the orchids in a room with relatively cool temperatures will help guard against dehydration. Most orchids are actually most happy at temperatures below the comfort level of humans, especially at night. Orchid greenhouses are usually maintained at 55-65 degrees at night and 70-80 degrees during the day.
Potting mixes for tropical orchids are loose mixtures of organic material such as fir bark (not pine bark), with any of the following added in smaller amounts: cypress mulch, tree fern fiber, peat, perlite, cork, or charcoal added. The object is to have a mix that drains well but holds some moisture. Most commercial orchid growers supply ready-to-use orchid mixes in small quantities (see our catalog or web site). Most epiphytic orchids need repotting only once every two to three years depending on your watering habits and growing conditions.
In watering orchids, it is best to soak the potting mix thoroughly and wait until the surface is relatively dry before watering again. Most mature orchids in fir bark-based mixes will need watering no more than once every 5 to 7 days.
All plants can be fertilized safely with a weak solution of urea-free fertilizer such as Growmore 20-10-20 or Dyna Grow Orchid Pro 7-8-6 once a month. Always water before fertilizing and remember that it is better to under-fertilize rather than to over-fertilize. With the lower light and drier conditions in the home, orchids cannot use as much fertilizer as they can use in the greenhouse and only every 6-8 weeks might be necessary for happy plants. Some growers like to increase the humidity around their orchids in the home by using "humidity trays" or trays of wet gravel around or under the plants. Pots should not touch the surface of the water.
Note: This guide is applicable to many varieties of epiphytic orchids such as Brassias, Cattleyas, evergreen Dendrobiums and some Oncidiums. For other varieties, please click on one of these links: