Phalaenopsis (Moth Orchid)
Phalaenopsis is one of the easiest orchids to grow in the home and are available widely and inexpensively.With proper care, their blooms last for months and they readily rebloom. They are a tropical epiphytic orchid, meaning that in nature they grow on the branches and trunks of trees, but are not parasitic. Phalaenopsis orchids are monopodial, growing vertically from a terminal growth point. One or two new leaves will appear at the top of the plant each year, while the older leaves at the base of the plant will die. Phalaenopsis orchids are native to southern China, Taiwan, Southeast Asia, and New Guinea.
Phalaenopsis are categorized as low light orchids. Indirect light is best, but placement in a window with intense, direct light is acceptable if there is protection by a sheer curtain. Sunburn can occur very rapidly in strong, direct sunlight. Olive green foliage indicates the correct amount of light; dark green foliage means not enough light; red-tinged leaves indicate too much light. Insufficient light will hinder or prevent blooming.
Phalaenopsis orchids are warm growing, meaning they prefer temperatures in the 60s at night and between 70 and 80 degrees F during the day. The temperature difference between night and day is important. Upper and lower limits are 95 degrees F and 50 degrees F respectively. Temperatures close to a window may be hotter or colder than the temperature in the room. Rapid changes in temperature and drafts cause bud drop. Night temperatures to 55 degrees F for several weeks in autumn initiate flower spikes.
The culture medium and plant size determine how often to water. Water plants growing in sphagnum moss less frequently than those grown in bark, as bark is less water-retentive. If the plant is potted in sphagnum moss, water when the top of the moss feels dry. For a mature plant grown in bark, watering thoroughly once a week is usually sufficient. Small plants and seedlings may require more frequent watering. Higher heat and light conditions may require more frequent watering. Since this orchid has no water-storing capacity except in its leaves, it should never completely dry out. Do not use salt-softened water on your Phalaenopsis.
Do not use ice cubes to water your plant. Phalaenopsis are shocked by cold temperatures, causing root death. In addition, a few ice cubes do not provide enough moisture. Water your orchid in the morning so the leaves will dry before nightfall. Wet foliage at night is conducive to causing disease. Place the plant in the sink and flood for a minute or so with lukewarm (never cold) water. Allow the plant to drain completely. Assure that there is good pot drainage, i.e., holes in the bottom of the pot. Soggy roots will rot. If water remains in the crown of the plant wick it out with a paper towel to avoid crown rot.
Tropical orchids prefer humidity of 50% or higher. If humidity in the home is below this threshold, you can place your plant in a shallow tray of pebbles with water on the bottom. Be sure that the bottom of the pot is not in the water or the roots will rot. Provide air circulation around plants.
Fertilize your plant once each week after watering, or three weeks out of four. Use a balanced orchid fertilizer such as 20-20-20 at half strength the recommended concentration on the label. During winter, fertilize at quarter strength. Orchids are harmed by a high concentration of fertilizer. Depending upon the time of year, other formulations may be used. Fertilizers are salts. To avoid salt buildup flush the pot thoroughly with clear water once a month.
Phalaenopsis orchids should be repotted about every two years or when the potting medium is decomposed. If brown particles from breakdown of bark drain from the pot during watering, the bark is no longer satisfactory.If you insert your finger into the bottom hole in the pot and the bark is no longer firm, it is time to repot. It is best to repot in spring or summer, and just after the plant has completed its bloom cycle. Remove the plant from the pot, wash the roots and remove any dead roots. Live roots will be whitish, firm and plump; dead roots will be brown, wiry and dry. Use a sterile razor blade or sterile pruner to remove them. Always sterilize your tools between plants so as not to spread disease. Use a suitable disinfectant such as bleach. Either plastic or clay pots are acceptable, but the pot must be clean and sterile. Both plastic and clay offer advantages and disadvantages. Proper drainage is essential.
Purchase a commercial orchid potting medium labelled for Phalaenopsis orchids. Usually these are fir or sequoia bark based and may include horticultural charcoal and perlite. For a mature Phalaenopsis orchid, use a medium grade bark size. Do not pot in standard plant potting mix, as this results in root rot and plant death. The potting medium must be porous. Spread a layer of potting medium in the bottom of the pot and place the plant in the center of the pot, spreading the roots. Fill the rest of the pot with culture medium, using your hands to maneuver the bark in between the roots. The junction of the stem and roots should be at the top of the potting medium. Pot for the size of the root mass; avoid overpotting. Use a pot that will accommodate the roots but not be excessively large, as this could compromise the plant. You may have to go to a smaller pot. Label the orchid and write the repotting date on the label to keep track of when it needs to repotted again.
Phalaenopsis orchids are one of the longest blooming orchid genera, with blooms lasting 2 to 6 months from late winter to spring. As the flower spike grows vertically, you will need to stake it for support. It is very tender and will break easily. As the buds and flowers develop, the stake will also carry their weight. While the flower spike is shooting up, do not change the light orientation of the plant to prevent the flower spike from twisting toward the light and becoming unattractive.
After your orchid has lost its last bloom it is time to remove the flower spike. Cut off the old flower spike near its base. This encourages the plant to rebloom within a year. You can initiate lateral flower buds on the old spike by cutting it above the second node (the brown lines on the stem); however, this weakens and stresses the orchid.