Phalaenopsis, (fail-eh-NOP-sis) the moth Orchid, is
perhaps the best Orchid for growing in the home, and is also a favorite with
greenhouse growers. Well-grown plants can flower often, sometimes with a few
flowers throughout the year, though the main season is late winter into spring.
Average home temperatures and conditions are usually sufficient. Flower stems
on certain hybrids can be forced to rebloom by cutting the tip off after the
initial flowering. Only healthy plants should be induced to flower repeatedly.
Culture for Doritis, a related genus, thought by some to be conspecific with
Phalaenopsis, and Doritaenopsis, a hybrid between the two genera, is the same
as for pure Phalaenopsis.
Light. It is easy
to provide for Phalaenopsis. They grow easily in a bright window, with little
or no sun. An east window is ideal in the home; shaded south or west windows
are acceptable. In overcast, northern winter climates, a full southern exposure
may be needed. Artificial lighting can easily be provided. Four fluorescent
tubes in one fixture supplemented by incandescent bulbs are placed 6 to 12
inches above the leaves, 12 to 16 hours a day, following natural day length. In
a greenhouse, shade must be given; 70 to 85 percent shade, or between 1,000 to
1,500 foot-candles, is recommended. No shadow should be seen if you hold your
hand one foot above a plant's leaves.
Phalaenopsis should usually be above 60 F at night, and range between 75 and 85
F or more during the day. Although higher temperatures force faster vegetative
growth, higher humidity and air movement must accompany higher temperatures,
the recommended maximum being 90 to 95 F. Night temperatures to 55 F are
desirable for several weeks in the autumn to initiate flower spikes.
Fluctuating temperatures can cause bud drop on plants with buds ready to open.
Water is especially critical for Phalaenopsis. Because they have
no major water-storage organs other than their leaves, they must never
completely dry out. Plants should be thoroughly watered and not watered again
until nearly dry. In the heat of summer in a dry climate, this may be every
other day; in the winter in a cool northern greenhouse, it may be every 10
days. Water only in the morning, so that leaves dry by nightfall, to prevent
Humidity is important to Phalaenopsis, the recommended
humidity being between 50 to 80 percent. In humid climates, as in greenhouses,
it is imperative that the humid air is moving. Leaves should be dry as soon as
possible, always by nightfall. In the home, set the plants on trays of gravel,
partially filled with water, so that the pots never sit in water.
Fertilize on a regular schedule, especially if the weather is
warm, when the plants are most often growing. Twice-a-month applications of
high-nitrogen fertilizer (such as 30-10-10) are appropriate where bark-based
media are used. Otherwise, a balanced fertilizer (such as 10-30-20) can be
applied to promote blooming. Some growers apply fertilizer at one-quarter
strength with every watering; this is best for warm, humid conditions. When
cooler, or under overcast conditions, fertilizer should be applied twice per
month at weak strength.
Potting is best done in the spring,
immediately after flowering. Phalaenopsis plants must be potted in porous mix.
Potting is usually done every one to three years. Mature plants can grow in the
same container until the potting medium starts to decompose, usually in two
years. Root rot occurs if the plants are left in a soggy medium. Seedlings
usually grow fast enough to need repotting yearly, and be repotted in
fine-grade medium. Mature plants are potted in a medium-grade mix. To repot,
remove all the old medium from the roots, trim soft, rotted roots, and spread
the remaining roots over a handful of medium in the bottom of a new pot. Fill
the rest of the pot with medium, working it among the roots, so that junction
of roots and stem is at the top of the medium.