Phalaenopsis Orchid (Moth Orchid): Care and Growing Guide (For Beginners)

By Jessica Nolan, Gardening Expert Houseplants

The Phalaenopsis orchid (Moth orchid) is a genus of exotic-looking flowering plants in the family Orchidaceae. Also called the moth orchid, phalaenopsis orchid has flowers with colorful petals, large leathery leaves, and long epiphytic aerial roots. Species of phal orchids are popular indoor plants because they are easy to care for.

The spectacular feature of orchids in the genus Phalaenopsis is their exotic flowers. The flowers of Phal orchids last for several weeks, and the orchid stems can produce many flowers at once. Phalaenopsis orchids flowers tend to bloom when temperatures drop below 60°F (15°C). Phalaenopsis flowers can be white, mauve, pink, purple, or striped with orange or red markings.

This article is a guide for growing phalaenopsis orchids as houseplants indoors or outdoors in warm, humid climates. At the end of the article, you’ll learn how to resolve various issues with phalaenopsis orchid flowers, how to get them to rebloom, and what to do about orchid plant pests.

How to Care for Phalaenopsis Orchid Indoors or Outdoors

To care for a phalaenopsis indoors or outdoors, grow the moth orchid in bright light, protected from direct sunlight. Plant the phal orchid in a loose, bark-based potting mix that gives the roots plenty of air. Water often enough to keep the orchid mix damp. The best temperature for growing Phalaenopsis orchids is between 60°F to 85°F (15°C – 29°C).

You can grow species of phalaenopsis orchids outdoors. These heat and humid-loving plants thrive in the ground or growing on trees in USDA zones 10 through 12.

What is Phalaenopsis Orchid (Moth Orchid)?

Phalaenopsis is a genus of orchid that is native to India, Southeast Asia, and Australia. Phalaenopsis orchids or moth orchids are identified by their two large petals and three oval sepals. As with other epiphytic flowering plants, orchids have long, coarse roots that absorb moisture and nutrients from the air.

The botanical name for these orchids, Phalaenopsis, means “like a kind of moth” in Greek. The common name moth orchid comes from the fact that the naturalist who first described the phalaenopsis orchid mistook clusters of Phalaenopsis flowers for masses of fluttering moths. Sometimes, these orchids are called Phal orchids.

Phalaenopsis Orchid Flowers

Masses of Phalaenopsis flowers grow on arching spikes or stems. The beautiful, unusual flowers are characterized by large colorful, oval petals. Moth orchid flowers have a specialized petals that attract pollinators. Phalaenopsis orchid flowers are generally star-shaped with petals that are widely spread apart.

How Long do Phalaenopsis Orchids Bloom For?

Moth (phalaenopsis) orchids bloom for three months or longer. Small flower buds grow on long flower spikes. Multiple flowers on the flower spike cause it to bend over with the weight of the blooms. So, for the three months while the phalaenopsis orchid is blooming, you’ll need to support the flowering stems.

How to Get Phalaenopsis Orchid to Bloom Again

After the flowers drop, you may be wondering: “How can I get my phalaenopsis orchid to rebloom?” Moth orchids bloom for a long time during winter and early spring. Phal orchids bloom again when temperatures are around 55°F (13°C). These orchids bloom again in fall when average nighttime temperatures are around 10°F (8°C) colder that the daytime temperatures.

You can encourage your phalaenopsis orchid to bloom by putting it in a colder place in temperatures between 55°F and 60°F (13°C – 15°).

Some studies found that phalaenopsis orchids bloom when average temperatures are 57°C to 62°F (14°C – 17°C). The research suggested that fluctuations between day and night temperatures aren’t necessary for moth orchids to bloom again. However, phalaenopsis orchids won’t bloom when the daytime temperature is over 84°F (29°C).

Phalaenopsis Orchid Care for Beginners

Phalaenopsis orchids are exotic plants that are easy for beginners to care for. Let’s look in more detail at the care requirements for growing moth orchids indoors.

Light Requirements for Growing Phalaenopsis Orchid Indoors

Phalaenopsis orchids thrive in bright light if the plants have protection from direct sunlight. Phalaenopsis can grow in low-light conditions and will perform well in partially shaded areas. An excellent place to grow a phalaenopsis orchid indoors is on an east- or west-facing windowsill. In a south-facing room, keep the orchid away from the window.

Too much direct, intense sunlight causes the thick leathery orchid leaves to become yellow and wilt. In their native habitat, phalaenopsis orchids grow attached to tree trunks under the forest canopy. This means that moth orchids prefer dappled sunlight.

You can grow a phalaenopsis orchid outdoors in USDA zones 10 through 12. The moth orchid thrives in gardens as long as it’s at least 60°F (15°) and growing in filtered sunlight. You can also take indoor phalaenopsis orchids to grow outside during warm summer days if you live in temperate climates.

Best Soil for Phalaenopsis Orchid

The best potting medium for a phalaenopsis orchid is tree bark chips with some sphagnum moss, perlite, or coconut husk chips mixed. Alternatively, you can use a commercial potting mix for orchids. The soilless mix for phalaenopsis should be light and airy.

Phalaenopsis orchids grow as epiphytes on trees. Epiphyte plants grow on the surface of other plants and get moisture and nutrients from the rain and air. Their aerial roots also absorb nutrients from decaying matter on the surface of the host plant.

Here are some handy tips on choosing the best pot for growing phalaenopsis orchids indoors:

Choose a transparent plastic pot so that the aerial roots get plenty of light.
Make sure there are ventilation or drainage holes in the container to prevent an overly-moist potting mix.

Related reading: How to make the best soil mix for orchids.

How to Water Phalaenopsis Orchid

Water a phalaenopsis orchid as often as once a week to ensure the potting mix is always slightly damp. When the moth orchid blooms, you can water the orchid every two weeks. Phalaenopsis isn’t a drought-tolerant plant as there is no effective way for the orchid to retain water.

It can be tricky to get a watering technique right for phalaenopsis orchids. Here are a few handy tips on watering phalaenopsis indoors:

Don’t let water pool around the orchid’s stem as rot will set in, and your beautiful orchid could die.
Avoid getting water on the orchid’s leaves and flowers.
Stand the orchid pot in a few inches of water for about five minutes and let the roots absorb as much water as they need.
Occasionally giving your moth orchid’s potting mix a thorough soaking can help keep the soil moist and plant hydrated.
Don’t allow the roots to sit in soggy, overly-damp soil.

Top tip for phalaenopsis orchid care: White-gray roots are a sign that the orchid needs water.

Temperature Requirements For Growing Moth Orchid Indoors or Outdoors

The phalaenopsis orchid grows well in temperatures between 60°F and 85°F (15°C – 29°C). Average indoor household temperatures between 72°F and 78°F (22°C – 25°C) are ideal for growing moth orchids indoors. To get your orchid to bloom, the temperature should be below 60°F (15°C) for a few weeks.

Phalaenopsis orchids grow outdoors in partial shade in rock gardens or tied to trees. The average temperature to grow moth orchids outside should be above 55°F (13°C) because orchids don’t grow well in the cold.

Phalaenopsis Orchid Care – Humidity Requirements

Keep humidity levels between 50 and 60 percent to care for phalaenopsis orchids. In their natural environment outdoors, moth orchids thrive in humid conditions. In hot temperatures, they may need even more humidity. However, if you’ve got high air moisture, there must also be good air circulation to prevent root rot and fungal infections.

To care for orchids indoors, it’s crucial to increase humidity around the tropical plants. You can place the moth orchid pot on a gravel tray that is half-full of water. The evaporating water creates a humid atmosphere for your orchid. Alternatively, you can use a humidifier to boost air moisture levels.

Related reading: The best closed terrarium plants.

Should you mist phalaenopsis orchids indoors?

Should you mist phalaenopsis orchid leaves? Generally, it’s best not to mist orchid leaves. Misting orchid leaves doesn’t increase humidity as it just dampens their leaves. Another reason not to mist moth orchid leaves is that you can cause mold spots on the leaves or flowers.

How to Fertilize Phalaenopsis Orchid Plants

The time to fertilize orchids is from after they finish blooming in spring until October. Apply a diluted orchid fertilizer every week or two to help a moth orchid grow faster and healthier. It would be best to reduce fertilizing a phalaenopsis orchid to once a month due to its slower growth during winter.

Propagating Moth Orchid

Propagating a phalaenopsis orchid is usually by repotting new plants that grow from the parent plant. These baby orchids called Keiki are copies of the mother plant. Remove the baby plant once it has two or three leaves and its own roots. Repot it in a new pot with a suitable orchid potting mix.

You can propagate phalaenopsis orchids by seed. However, this is a time-consuming process and it’s difficult to produce results.

Repotting a Phalaenopsis Orchid

Healthy phalaenopsis orchids benefit from repotting every two years. Transferring the moth orchid to a larger pot gives the roots more room to grow. You can also use the repotting time to refresh the orchid potting mix and check the roots for damage.

The best time to repot a moth orchid is in late spring or summer after the blooms have dropped off. Remove the orchid from its container and inspect the roots for signs of damage. Healthy roots should be a vibrant green color and look plump. Discard the old potting mix. Sterilize the new pot and put the orchid in it. Then fill the remaining space with the orchid potting bark mix.

How to Prune Phalaenopsis Orchids

The only pruning you need to care for moth orchids is to cut off unhealthy roots. Look for aerial roots that are withered, mushy, or appear damaged. It is OK to take sharp shears to remove rotten roots. You shouldn’t worry about cutting off damaged roots as the orchid’s growth will benefit from it.

You may be wondering what to do about phalaenopsis orchid stems after flowering. You can either prune the flowering spikes at a node. If the stem has grown long and leggy, you can cut the complete stem off to improve your orchid’s appearance.

Common Pests Affecting Phalaenopsis Orchid Growth

Moth orchids are susceptible to common houseplant pests such as spider mites, mealybugs, scale insects, aphids, and thrips. Get rid of bugs from orchids by making a neem oil natural pesticide. Spray the thick leathery leaves once a week to kill mites, pests, and bugs.

To make a neem oil spray solution for orchid care, mix 2 tsp. neem oil and 1 tsp. liquid Castile soap in 1 quart (1 l) of warm water. Thoroughly mix in a spray bottle to use on your orchids and other infested houseplants.

It’s vital to spot the early signs of a pest infestation on a phalaenopsis orchid. Pest attacks can leave your beautiful orchid flowers mottled and distorted or cause leaves to turn yellow and curl. A black sooty mold fungus can also grow on orchid leaves.

Here are signs of common orchid pests:

Aphids—These pests look like tiny pear-shaped green, black, or brown insects that congregate under orchid leaves.
Mealybugs—It’s easier to spot mealybugs because these pests look like small white fuzzy creatures that leave a cotton wool-like substance behind.
Spider mites—The first signs of spider mites are silky webs that dangle from orchid leaves or stems. There may also be webbing around leaves.
Thrips—Thrips are tiny flying insects that lurk underneath leaves. Thrips can damage orchids by feeding on the plant’s sap.
Scale insects—You may notice scale insects as unusual bumps on the orchid’s stems. Similar to other houseplant pests, scale can cause much damage to orchids.

Common Diseases Affecting Phalaenopsis Orchid Growth

Fungal diseases are common on moth orchids if the foliage or roots are excessively damp due to overwatering or poor air circulation. Usually, good drainage and proper watering to keep the potting mix slightly moist are enough to prevent fungal orchid diseases. Also, avoid splashing water on the leaves when watering orchids.

Suppose you notice signs of disease on an orchid’s leaves or roots. In that case, it’s vital to resolve the underlying issue. To help save a dying phalaenopsis orchid, change the potting mix to ensure that it drains well and enough air circulates. To care better for your moth orchid, only water the potting mix enough to keep it slightly moist.

Phalaenopsis Orchid Care After Flowering

After a phalaenopsis orchid blooms in late spring, proper care ensures the plant blooms again the next fall. You can do three things after the orchid blooms: leave the flower stem, cut it back to a node, or cut the spike completely. Removing the stems depends on the type of phalaenopsis that you have.

Most orchid owners recommend cutting phalaenopsis stems at their base after flowering. Snipping off the flower spike helps the orchid to develop healthy roots. Removing the flower spike is useful if it’s grown long and unruly. The orchid will produce a new stem and bloom again in late fall when the temperature drops.

Alternatively, you can cut the phal orchid flower stem back to a node. This type of moth orchid care allows the plant to rebloom from a branch on the existing spike. If you have a large, healthy phalaenopsis orchid, then snipping the stem at a node is often the best option.

Why Phalaenopsis Orchids Need Cool Temperatures to Bloom

Phalaenopsis orchids generally bloom when nighttime temperatures are around 10°F (8°C) colder than daytime temperatures. Ideally, the moth orchid should get a few weeks of temperatures between 55°F and 60°F (12°C – 15°C) to bloom. You can also encourage your phalaenopsis to bloom by moving it to a cooler location.

When getting a moth orchid to rebloom, it’s vital to protect it from drafts. Sudden changes in temperature, such as a cold draft, can affect the orchid’s growth. Similarly, it would be best to protect the orchid from warm airflow from a heating duct.

What Should I do About Phalaenopsis Orchid Aerial Roots?

It is best to leave aerial roots on phalaenopsis orchids alone. The long straggly roots absorb light, moisture, and nutrients like all epiphytic plants. So, there is nothing wrong if the roots poke out the potting mix.

Orchid roots are also useful for knowing if you need to water the plant. Orchids in need of hydrating have roots that are white and shriveled. However, a well-cared-for moth orchid has roots that are greenish-gray and plump.

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