Light
Sufficient light is important for healthy growth and flower production. Provide
bright light, no direct sun. In the home, place the orchids in an east, west or
shaded south window. In a greenhouse, give them about 30 percent full sun. Under
lights, use four 40-watt fluorescent tubes and two 40-watt incandescent bulbs
directly over plants.
Foilage should be naturally semi-erect, and of a medium olive-green
color. Dark green, limp foilage 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
5 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 a greenhouse, use a humidifier if conditions are too dry.
Fertilizer
Must be provided on a regular basis because potting medium has little. 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 fertilizer (10-10-10, 12-12-12
or similar ratio) "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 the main flowering season, using a well-drained but
water-retentive mix. Select pot size for root mass, not top size.