A full size Phalaenopsis can very possibly be in bloom for 6 to 8 months out of the year; producing two or more complete spikes per year. When the last flower has wilted, the spike can be cut back to about an inch above the fourth node, counting from the base. (A node is the bump on the spike.) Usually, a lateral shoot will form from one of these remaining nodes within several months.
Temperature – A minimum night temperature of 62° to 65° F is optimum. Temperatures as low as 58° F will not harm the plant and would be helpful to initiate spiking, but should not be continued for more than a few weeks as the plants are more prone to fungus at these temperatures. Day temperatures should range between 75° to 85° F.
Humidity and Ventilation – A relative humidity of 50% to 60% is ideal. Good air movement is essential if your humidity is extremely high. In greenhouses fans should be used, but in the home it is not as critical.
Light – Phalaenopsis prefer moderate levels of light, with NO direct sun. They do best in an east or west window that gets very early of late sun but without direct sun the rest of the day. They can also be grown in a south facing window if shaded or kept back from the window. They also do well under artificial light, or a north facing window that is open to the sky and gets very bright light.
Watering and Feeding – Always water orchids in the morning so that the plants are dry before sunset. How often to water depends upon the potting media used, the type of pot (clay or plastic), and the size of the pot. Strive for a damp media, not soaking, and never allow the plant to become bone-dry. When you water, water well, then let the plant become just moist before watering it well again. For Phalaenopsis in bark mixes feed with Peters 30-10-10 every two weeks in the summer, every three weeks – spring and fall, and once a month in the winter.
Pests – Mealy bugs, slugs and snails are probably the worst pests of Phalaenopsis. Slugs and snails can be controlled with products containing Metaldehyde, such as Deadline. Diatomaceous Earth is quite effective against slugs and beer in a shallow bowl is a good trap for them. Mealy bug and other pests can be controlled with insecticides like Malathion or X-clude. REMEMBER, these products are intended to kill and should be used in the open air outside your home. A light horticultural oil, like Year Round, (not a dormant oil) which smothers bugs and their eggs is quite effective against most pests and fairly safe. Also effective against mealy bug, aphids and other pests is Insecticidal Soap, which is not a poison. Use any of these products with caution and in accordance with the manufacturers label.