Phalaenopsis Orchid Plant Profile

A closeup of a Phalaenopsis orchid
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The orchid group includes several several hundred different genera and thousands of species, but most people are introduced to orchids through the Phalaenopsis genus, which are particularly good orchids for beginners. These are thick-leaved plants with elegant, arching sprays of bloom—the orchids featured in so many design magazines sitting on coffee tables across America.

Phalaenopsis orchids are rewarding plants. They are not demanding, and in the right conditions, they will display showy blooms for months.

Botanical Name:  Phalaenopsis spp.
Common Names:  Moth orchid, Phalaenopsis, phals
Plant Type:  Herbaceous flowering perennial, orchid group
Mature Size:  8 to 36 inches tall (depending on species and variety), 12 inches wide 
Sun Exposure:  Bright shade
Soil Type:  Moist, bark-like potting media
Soil pH Slightly acidic to neutral
Bloom Time:  Spring and summer; indoors, it is a repeat seasonal bloomer
Flower Color:  White, pink, lavender, yellow
Hardiness Zones:  10 to 12, USDA
Native Area:  Southeast Asia to the Philippines, New Guinea and northern Australia 
Blooms of the yellow striped moth orchid
Jena Ardell / Getty Images

How to Grow Phalaenopsis Orchids

Phalaenopsis orchids are hardy in zones 10 to 12, where they can be grown outdoors in warm, humid conditions that are damp but not soggy, in a location that is shady but bright (no direct sun). More often, these plants are grown as indoor potted plants, where successful growth means finding the right balance between humidity, temperature, light, and airflow. Their long-lasting flowers are held on arching branches and open successively. A single multi-branching flower spike can have more than 20 flowers, and individual flowers can last for weeks.

Light

Good light is required for phalaenopsis but they can experience absolutely no direct sunlight, or the leaves will scorch. Rotate the plant from time to time to keep growth equal. Phalaenopsis can tolerate low light and will thrive in an east window, or a shaded southerly or westerly exposure. Also, they will do well under common grow lights positioned about a foot from the plant. A well-grown plant will have darker green leaves on top and streaks of red or burgundy on the undersides.

Soil

In native conditions, moth orchids grow on trees as epiphytes—a type of plant that requires a host plans. Instead of regular soil, they need potting material that mimics a host tree or comes from a tree, such as ground fir tree bark, redwood bark chips, or Monterey pine bark chips. Most bark potting media will work. Also, make sure there is some perlite, sphagnum moss, charcoal, or coconut husk chips mixed in to help with water retention. You can also buy a commercial potting mix that is made special for orchids. No matter the potting media you use, make sure there is plenty of air circulation for the rooting system. Epiphytes are accustomed to breezes and wind and don't do well without it.

Water

Phalaenopsis is a monopodial orchid, which means that it grows from a single stem. It does not have the large water-storing pseudobulbs found on sympodial orchids, although its leaves can store some water. Thus, this plant has a lower tolerance for drought.

During the growing season, water the plant weekly or whenever its exposed roots turn silvery white. Water them in the morning and try to keep the potting media slightly damp. During the flowering season, you can cut the water back to every other week. Water should never be allowed to rest around the stem of the plant. This will cause the new leaves to rot, and the plant will die.

Temperature and Humidity

Phalaenopsis orchids are considered warm houseplants. During active growth, they like temperatures between about 75 and 85 degrees F., but they can adapt to a normal house temperature of 65 to 70 degrees. The higher the temperature, the greater the plant's need for humidity. As with all orchids, the higher the humidity and temperature, the greater the need for turbulent airflow to prevent rot, fungus, and diseases. Many successful orchid growers keep a ceiling fan or stationary fan running constantly in rooms where they grow orchids.

These plants also like a nice contrast between night and day temperatures. To induce a flower spike, the plant needs a few cooler nights, down to 55 degrees. The plants will not bloom well without this temperature contrast.

Fertilizer

During the growing season, fertilize with a weak orchid fertilizer weekly ("weakly weekly," as the growers say). Cut fertilizer back to once a month during the winter and flowering season. Some growers like to give the plant a boost of blooming fertilizer in September or October to provoke a flower spike.

Propagating

Orchids are propagated by seed, but the process can be time-consuming. Periodically, the plant will naturally produce "baby" orchids known as a keiki. These are identical copies of the parent and normally appear on either an old or new flower spike. After the keiki is about a year old, you can remove it from the parent plant and give it its own pot. The keiki is ready after it has two or three leaves and its own roots (about 3 inches long).

Varieties of Phalaenopsis

There are about 60 true species of phalaenopsis orchids. These plants have been extensively hybridized, and there are thousands of hybrids, ranging from the stark, classic white hybrid moth orchid to jewel-like miniatures with clouds of yellow and candy pink blooms. New hybrids are developed constantly.

Growing in Containers

Phalaenopsis can be grown in most orchid potting media. Repot phalaenopsis in spring, after the bloom is done. Adult phalaenopsis can often go for two years or more before they need to be repotted.

They can also be grown in hanging baskets or mounted on slabs in a greenhouse-type environment. As with all epiphytic ( orchids (those that grow on surfaces) they should be planted in free-draining containers.

Common Pests/ Diseases

Phalaenopsis orchids have no critical insect or disease problems, but scale, mealy bugs, slugs, and snails are among the insect pests that occasionally occur. The plants can also be susceptible to root or stem rots, which usually occur because the growing medium is too soggy. Orchids can experience bud blast—a condition where the flower buds drop without blooming. This can be caused by sudden changes in temperature, humidity, moisture, or fertilizer.