The Moth Orchid
An American Orchid Society demographic survey showed that phalaenopsis have become America’s favorite orchid. And no wonder. Perhaps no other orchid is better suited to home orchid growing. Plants with long-lasting sprays of lovely mothlike blooms in a broad array of colors are inexpensive and widely available, ready to give weeks of pleasure in your home or office. Simply provide modest light and consistent moisture, and they will delight you with their relative ease of culture. The main flowering season is late winter into spring, though commercial growers today can make flowering phalaenopsis available year round.

Light
Sufficient light is important for healthy growth and flower production.
Provide: Bright light, no direct sun. In the home, an east, west or shaded south window. In a greenhouse, about 30 percent full sun. Under lights, four 40 watt fluorescent tubes and two 40 watt incandescent bulbs directly over plants. Foliage should be naturally semierect, and of a medium olive-green. Dark green, limp foliage indicates too little light.

Temperature
Mature plants need a 15° to 20° F difference between night and day.
Provide: Nights of 60° to 65° F; days of 75 to 85 F. Seedlings need temperatures five to 10 degrees higher than mature plants.

Water
Mature plants should seldom dry out between waterings. Seedlings need more constant attention to moisture.

Humidity
Phalaenopsis need 60 to 70 percent humidity. In the home, place on trays of moistened pebbles. In greenhouse, use a humidifier if conditions are too dry.

Fertilizer
Must be provided on a regular basis because most potting media have little.
Provide: The exact fertilizer you use will depend on the mix in which your plant is growing. A good general rule is to use a balanced (10-10-10, 12-12-12 or similar ratio) fertilizer “weakly, weekly.” That is, fertilize every week at one quarter to one half of the recommended dilution.

Potting
Should be done every one to two years before the mix breaks down too far. Best done in late spring after main flowering season, using a well-drained but water-retentive mix. Select pot size for root mass, not top size.

Courtesy of American Orchid Society
http://www.aos.org