The beautiful and delicate Phalaenopsis or Moth Orchid, as it is commonly called, is one of the most popular orchids. It is an easy plant for the beginner but also has many rewards for the experienced grower. It can be grown in the home or in the greenhouse and is a very reliable bloomer. When fully mature, the plant seems to bloom year-round.
Temperature and Light
Phalaenopsis must be grown in a heated greenhouse or in the home. They will grow at temperatures between 60° and 90° F, but the ideal maximum is 68° F at night and 85° F during the day.
Phalaenopsis do not have a high light requirement, but they must have adequate filtered sunlight at least part of the day in order to bloom. In the home, an east window (if unobstructed) is excellent. It may be necessary to place a sheer nylon curtain in the window to prevent sunburn. If the foliage begins to yellow, there may be too much light.
Water, Fertilizer, Humidity, and soil
Phalaenopsis cannot store water so they should not be allowed to dry out or kept too wet. A thorough soaking once a week should be adequate. It is best to prevent water from getting on the leaves. Do not use cold water — use tepid water to prevent tissue damage; we recommend adding SUPERthrive to every watering (1 drop per cup or ¼ tsp per gallon). Watering should be done in the morning on a sunny day so that the plant will dry out by nighttime.
Phalaenopsis should be fed every 2 weeks. Use Grow More Premium Orchid Food. Continue this feeding cycle year-round.
Humidity should be kept at 70% during the day and 50% at night. In the home, this can be achieved by placing the plant on a grid over a humidity tray. Never allow the plant to sit in water as it must be able to drain freely.
Phalaenopsis need to be repotted every 14 to 18 months; be sure the foliage is dry, and the planting medium is moist before repotting. We recommend using Kiwi premium-grade pine bark from New Zealand. After repotting, the plant should immediately be watered with tepid water with SUPERthrive added per above.
Phalaenopsis planted in clear plastic containers appear to bloom better than when planted in containers that don’t allow light to reach their roots.
Most Phalaenopsis bloom late winter into spring. When that blooming is through, the spike can be cut off above the 2nd or 3rd node (from the bottom). This node will then probably put out laterals and bloom again in the summer.
Our source for much of this information is the American Orchid Society Guide: Growing Orchids.