Orchids are becoming increasingly popular with many home plant hobbyists because of their beauty, long-lasting blooms, and affordability. A favorite among many is the moth orchid (Phalaenopsis species). Due to their resilience, these popular orchids are easy to grow. They can survive many of the inevitable mistakes, such as overwatering, that would kill less hearty plants.
Watering will depend on the potting medium. Bark retains less water than moss; therefore, watering once a week is generally sufficient. If potted in moss, water when the top feels dry to the touch, the amount of light and heat the plant receives will also affect how soon the moth orchid needs watering. During the summer months, the orchids will need more frequent watering, but in the winter, they will need less. One easy way to determine when to water is by the weight of the pot. If the pot feels heavy, then the plant does not need watering. A preferred method for watering is to place the container in the sink and use lukewarm water. Let the water run through the potting medium for a minute or so. Be sure to let the plant drain completely.
Moth orchids are ‘low’ light plants and grow best in indirect sunlight, preferably in an east-facing window. Do not let the foliage touch the cold glass during winter, as it will damage the foliage. They prefer a temperature range between 60 °F and 85 °F. Any balanced orchid fertilizer can be used, such as 10-10-10, from mid-spring through early fall. Spring through fall is also a perfect time to allow the orchids to grow outside and benefit significantly from the natural environment. Wait until the danger of the last frost has passed in the spring, and the nighttime temperatures are above 55 °F. Place in a shady area to prevent the sun from burning the leaves.
When the blooms have faded, prune the spike down to the level of the leaves. If properly cared for, the plant will produce a strong flower spike within a year. While waiting for the blooming cycle to begin again, continue to properly water and fertilize. Repotting is usually done every one to three years, shortly after the orchid finishes blooming. Do not repot when the orchid is in bloom as this will damage or kill the plant.
For more information on growing orchids, please see HGIC 1560, Orchids.