How to Grow and Care for Phalaenopsis Orchids Indoors

Phalaenopsis orchids, commonly called moth orchids, are one of the most popular orchids because they are easy to grow and care for as a houseplant. They often bear multiple flower buds on arching stems, which can last for two to three months.

If cared for properly, Phalaenopsis orchids live for 15 to 20 years in your home. Here's what you need to do to make that happen.

Phalaenopsis Orchid Care

Light

Like most orchids, Phalaenopsis needs bright, indirect light from a south- or east-facing window to produce blooms. Rotate your orchid from time to time to keep its growth even.

If there is not sufficient natural light, use a grow light with a fluorescent tube (40 or 74 watts depending on length). Place the plant about 12 inches below the light.

Soil

To mimic the native conditions where moth orchids grow on trees, potted orchids require a special orchid-growing medium that you can find at your local garden center. Standard potting mix is not suitable because it does not offer the air circulation around their root system that Phalaenopsis orchids require.

Water

In summer, while the orchid is growing, water weekly or when its exposed roots turn silvery white. The best way to water this plant is to put it in a sink or tub and run room-temperature water over it (plant, bark, and aerial roots) three to four times over the span of 10 minutes; this allows the orchid to absorb plenty of water.

Always let the plant drain entirely, as stagnant water around the stem can cause the roots, stems, and/or leaves to rot.

Temperature and Humidity

Phalaenopsis prefers temperatures between 75 and 85°F but adapts well to normal indoor temperatures of 65 to 70°F. Orchids also like contrasting night and day temperatures. To induce blooming, the plant needs a few cooler nights, with temperatures around 55°F.

Fertilizer

During the growing season, fertilize your orchid with a diluted orchid fertilizer (20-20-20 fertilizer at 1/4 strength) every three or four weeks. Skip feedings during the fall, winter, and spring flowering season when too much fertilizer will lead to excessive foliage and no bloom.

Types of Phalaenopsis Orchids

There are 61 true species of Phalaenopsis orchids and seven hybrids. Some popular types include:

• Phalaenopsis 'Liodoro' produces wavy, bright green leaves and pink and purple star-like flowers. This mature plant reaches a height of 19 inches.
• Phalaenopsis schilleriana boasts large 2.5-inch, pink and purple flowers, with dark green variegated leaves. Each stem on this variety grows up to 200 flowers.
• Phalaenopsis stuartiana produces white flowers with yellow and red dots on multiple branches. It reaches up to 30 inches in height.
• Phalaenopsis appendiculata is a miniature orchid that blooms in mid- to late-summer. It makes a good hanging plant. 
• Phalaenopsis amabilis, often called a moon orchid due to its bright white flowers, requires more light than other Phalaenopsis and the leaves take on a reddish edge. 

Pruning

Prune mature orchids once a year during their dormancy period, after the blooms have faded. Using clean scissors or a knife, cut the top portion of the stem back to one inch above a node to encourage a new stem section and more blooms. Deadheading it usually not necessary, as spent flowers just fall on their own.

Remove any brown or black leaves, and snip back unhealthy roots that are either dead and brown, or mushy. It is normal for your orchid to grow aerial roots above the soil; just let them be.

Propagating

Orchid lovers propagate their moth orchids by replanting the orchid's naturally produced "baby," known as a keiki. These identical copies of the parent periodically appear on either old or new flower spikes. After the keiki is about a year old, it is ready to be used for propagation.

1. Check if the keiki is suitable for propagation—three inches long with two or three leaves of its own and several good roots.
2. Carefully remove the keiki from the parent plant with sharp, sterilized scissors, keeping the roots intact.
3. Plant the keiki in a pot filled with damp potting medium.It's okay if the top parts of the roots are exposed.
4. Mist the baby plant daily with water until it becomes established.
   

Potting and Repotting Phalaenopsis Orchids

Repot Phalaenopsis orchids in the spring, after the bloom is done, or when you see roots growing out of the pot (about every two years).

1. Use a pot that is an inch or two bigger than the existing pot (disinfect it if necessary).
2. Let the pot dry fully, then fill it with a damp orchid potting medium.
3. Gently remove the orchid from its existing pot and cut away any brown roots.
4. Place the orchid in the new pot and gently firm the soil around the roots.
5. Mist daily until new roots form.

Common Pests & Plant Diseases

Moth orchids don't tend to have major pest problems. But they attract common houseplant pests, including aphids, fungus gnats, mealybugs, spider mites, scale, cigar-shaped thrips, and whiteflies. Most pests are easy to remove with a stream of water, insecticidal soap, or neem oil.

In addition to root rot from overwatering, orchids can also be afflicted with various fungal diseases, most often orchid root rot, phytophthora (black spots on leaves), botrytis, leaf algae, and petal blight.

How to Get a Phalaenopsis Orchid to Bloom and Rebloom

In the wild, Phalaenopsis orchids only bloom once a year. But indoors, you can get them to rebloom every six months with a few simple steps.

1. Once the last bloom has dropped, cut the brown stem off to no more than 3 inches in height.
2. Continue caring for your plant as normal and feeding it a diluted liquid fertilizer.
3. After the stem has grown a new leaf, relocate your orchid to a cooler area with temperatures of 55 to 65°F and bright indirect light.
4. After one month in this cooler environment, your orchid should produce new blooms.

Common Problems with Phalaenopsis

Wrinkled Leaves

If your orchid's leaves are wrinkled, you're likely under-watering and there's too little humidity. To increase the humidity, add a pebble tray with water below the plant, but don't let the pot sit in the water.

Yellow Leaves

Overwatering and root rot are often the cause of yellowing leaves. Give the orchid growing medium time to dry out between waterings. If that doesn't work, repot the plant and remove any unhealthy roots.

Buds Dropping

Orchids sometimes experience bud blast—a condition where the flower buds drop without blooming. This is usually caused by sudden changes in temperature, humidity, moisture, or fertilizer. Maintaining ideal growing conditions should lessen the occurrence of problems.