Orchids need good air circulation around their foliage and roots, and do best in non-soil growing foundations. Use heavy pots with drainage holes for balance and quick drying and put orchids in media like peat moss, fern matter, bark, gravel or vermiculite. Repot orchids every two years to maintain good nutrition.
Light, temperature and humidity make up the most important orchid-growing conditions. Keep orchids in soft, indirect or partial lighting, or in morning sun and afternoon shade, and maintain 50 to 80 percent humidity. Shoot for orchid-specific temperatures, ranging from nighttime temperatures of 40 to 50 degrees F for cool-weather orchids; 55 to 60 degrees F for intermediate orchids; and 60 to 68 degrees F for warm-weather orchids.
Orchids prefer dry, airy foundations and fail in standing water or tight, wet soil. Water them according to variety, but start with a general guideline of 1 to 2 inches of water every 10 days. Don't water the leaves or crowns of your orchids, as they'll rot. Alternate between 20-20-20 and 30-10-10 water-soluble fertilizer for orchids, recommends The University of Arizona Cooperative Extension of Mojave County. Mix the fertilizer at one-quarter the recommended rates to avoid burning the plants and add this to a biweekly watering.
The university extension also recommends switching to a phosphate fertilizer like 10-50-10 during an orchid's blooming season to encourage big, beautiful blooms. Phalaenopsis orchids bloom from April to June; Dendrobiums bloom in fall, winter and spring; Cymbydiums bloom in spring; and Oncidiums bloom virtually year-round.