Phalaenopsis orchids are warmth-loving flowers that enjoy most average indoor air temperatures and bloom in the spring. Native to Southeast Asia, Phalaenopsis orchids grow naturally in shady, moist environments in the undergrowth of forests. Also called moth orchids, Phalaenopsis are one of the most popular orchid types due to their ease of growing and beauty. There are hundreds of cultivated varieties of Phalaenopsis orchids, each with its own flower color and shape. Phalaenopsis orchids can bloom for up to four months during the year, but a mature one can bloom much longer.
Place your Phalaenopsis orchid in bright, indirect sunlight, such as an eastern-facing window or a shaded southern- or western-facing window. Don't expose the orchid to direct, full sunlight.
Maintain air temperatures around your Phalaenopsis orchid of 70 to 82 degrees Fahrenheit during the day and slightly cooler, but no colder than 60 degrees Fahrenheit, at night. Keep air temperatures below 78 degrees Fahrenheit to induce flowering.
Keep the humidity levels around the orchid between 50 percent to 80 percent by setting the plant's pot on top of a drip tray filled with gravel and water, with the container perched on the gravel and not sitting in the water. If you're growing the Phalaenopsis orchid in a humid greenhouse, ensure that a fan is turned on to circulate the air to prevent too much humidity and fungal diseases.
Water your Phalaenopsis orchid once every two to three days during the hottest part of summer and once every 10 days to two weeks during winter. Water the orchid thoroughly to soak the potting medium, and then allow the orchid to dry out slightly, but not completely, before watering again.
Feed the orchid half to one tsp. of 20-20-20 NPK liquid fertilizer each time you water the plant while it's actively growing. Feed the Phalaenopsis orchid once every third watering during fall and winter.
Repot your younger Phalaenopsis orchid once each year in late spring or early summer, when the plant is finished blooming. Gently remove all the potting soil from the roots, trim off any rotted roots and plant the orchid into a container that has drainage holes in the bottom, is the next size up and is filled with a fast-draining potting mixture.