Plants

Phalaenopsis

Phalaenopsis-Hybriden

Ulrike Hanninger Ulrike Hanninger

When you think of an Orchid, a Phalaenopsis or Moth Orchid will come to your mind. No other genus is as popular as this one. Tips for optimal indoor gardening.

Growth type
  • Perennial plant
  • rhizome
Growth height (from)
from 10.00cm to 40.00cm
Growth width (from)
from 20.00cm to 30.00cm
Growth characteristics
  • upright
  • rosette-forming
Flower color
  • purple
  • blue
  • yellow
  • orange
  • red
  • pink
  • white
  • multicolored
Flowering time (month)
  • January to February
  • October to December
Flower shape
  • Uniflorous
Flower characteristics
  • hermaphroditic
Leaf color
  • green
page format
  • wide oval
Sheet properties
  • evergreen
Light
  • scattered light to semi-shade
Soil Moisture
  • fresh to moderately humid
ph value
  • weakly acidic to acidic
Lime compatibility
  • sensitive to lime
Nutrient requirements
  • moderately nutritious
Humus
  • rich in humus
Decorative or utility value
  • Flower Decoration
Use
  • Interior greening
  • Winter garden
  • Warm House

Origin

Orchids of the genus Phalaenopsis are considered the epitome of the Orchids. They are among the best-selling ornamental plants worldwide and are by far the best-selling houseplants in the U.S. No wonder considering their enormously long flowering period and the almost infinite variety of colours.

The Phalaenopsis, also known as Moth Orchid (“phálaina” is Greek for moths), belongs to the family of Orchids (Orchidaceae). There are almost 100 species of the genus Phalaenopsis alone. They thrive as Epiphytes (non-parasitic plants that grow anchored to other plants) in the tropical forests of India, Indonesia and Australia; but they can also be found in New Guinea, Taiwan and the Philippines. Moth Orchids are accustomed to an evenly warm climate throughout the year, with only a few degrees cooler nights and hardly any seasonal fluctuations. The Phalaenopsis showcased here are all hybrids, i.e. hybrids of various types and forms of Moth Orchids. Thanks to years of cultivation, these are now perfectly suited for indoor gardening. They are considered the most easy-care indoor orchids and they can easily be kept on the windowsill.

Growth

Almost all Orchids of the genus Phalaenopsis have monopodial growth. That means they grow upwards and usually do not form side shoots. The roots are fleshy and don’t branch out too much, they are leafy green in color in areas exposed to light and can therefore also carry out photosynthesis. The size of the plants varies depending on the cultivated breed — for example,there are special mini-Phalaenopsis that grow barely four inches in height.

Foliage

Depending on the type and cultivated breed, the Phalaenopsis Orchid forms over two to six leaves, some are quite leathery, others can be quite fleshy. They vary in color and size. The leaves of small species such as the Phalaenopsis Appendiculata only reach a leaf length of approximately 3.93 to 15.74 inches, whereas species such as the Phalaenopsis Gigantea, nomen est omen, develop leaves up to 39.37 inches. The color ranges from light to very dark green and can be monochrome or mottled.

Blossoms

The flowers either grow sideways of the shoot axis under or between the leaves upright upwards and are arching overhanging or drooping. They can either be very delicate or waxy and stiff. The length of some varieties is 0.39 inches up to 5.90 inches. They are zygomorphic, which means that they consist of two mirror-like halves. There are Phalaenopsis flowers in all the colours of the rainbow, from white, rosé and red, to pink, purple or yellow. Patterned (e.g. Phalaenopsis Amboinensis Flavida) or fragrant specimens are also commercially available. The Phalaenopsis 'Liodoro' exudes a citrusy fresh fragrance.

Orchids in the greenhouse

There are almost 100 species of Orchids in the Genus Phalaenopsis. They are cultivated in all colors

Location

Phalaenopsis thrives best at room temperature with high humidity. A bright to semi-shaded place without direct sunlight is ideal. Avoid drafts as well as dry heating air. The temperature should be between 64.4 and 68 degrees Fahrenheit during the day and at least 60.8 degrees Fahrenheit at night. Temperature reducing by at least 39.2 degrees Fahrenheit at night is good for the plant.

Substrate

The commercially available Orchid soil works well as a substrate. It is very loose, crumbly and well-drained. It consists mainly of bark and peat. Although nowadays, peat is often replaced by coconut fibres, since it is an eco-friendly option. Cork can be added for better ventilation. Perlite and vermiculite store trace elements and slowly release them to the plant. You can also add activated carbon, which absorbs harmful metabolic products and thus makes them harmless.

Our tip: Do not switch between different substrates. If your Orchid is accustomed to a mixture, you should continue with it, as the plant takes time to get used to a new substrate.

Phalaenopsis Hybrid ‘Little Kolibri’

The flowers of the Phalaenopsis hybrid 'Little Kolibri' have a unique magenta colored grain

Watering

As with most Orchids, waterlogging must also be avoided urgently for Phalaenopsis. For easier dosage you can use a watering can with a narrow neck or a spray bottle. Rainwater at room-temperature is ideal. If excess water does accumulate, remove it as soon as possible. Many Orchid owners swear by weekly baths: The plant along with the pot is placed in a bowl filled with room-warm rainwater or tap water with less lime content (decalcified) for about half an hour. Then drain the water, leave the pots to drain for an hour in the empty bowl and put the Phalaenopsis back in the pot on the windowsill

Fertilizing

Phalaenopsis is a wild plant and is an epiphyte that requires very small amounts of nutrients. So it doesn't need a lot of fertilizer as an indoor plant either. If at all, use special Orchid fertilizers as available in specialist shops. Fertilizer should be added according to the instructions. Preferably add a little less than recommended because the Moth Orchid is very sensitive to highly concentrated fertilizer salts. If you bath your plants in water every week, simply add a low-dose of liquid Orchid fertilizer every other week. To avoid excess fertilizer getting wasted in the bath water, use this water for your balcony flowers or potted plants.

Repotting

About every two years the Phalaenopsis needs a new pot and above all fresh substrate. The ideal time to repot is in spring or fall. We also recommend special Orchid soil as it is precisely formulated to the needs of the plants and is quite crumbly and airy. A good drainage reduces the risk of waterlogging.

Water the Orchids using a spray bottle

After repotting, do not water the Phalaenopsis, but only moisten it a bit using a spray bottle

Carefully remove the plant from the container and take care not to damage the roots. Free them from the old soil and check carefully for rotten roots. You should remove these immediately with sterile and sharp pruning shears. The new pot — ideally an orchid pot with a built-in step, which also prevents waterlogging — can be the same size or slightly larger than the previous one. Allow the new substrate to trickle in and shake the pot gently again and again so that the soil can settle and spread everywhere. Important: Do not water the Phalaenopsis after repotting! Instead, the Moth Orchid prefers a spray bottle for the first two to three weeks. Only when it forms new leaves after repotting should you water it again with the watering can or treat it to a bath.

Pruning

Generally it is easy to prune Orchids and keep them in shape. If a stem of the Phalaenopsis dries up or turns brown, it can be cut off directly at the base. In case the main shoot of the Monopodial Genus withers, the whole stem can be trimmed back up to the third eye. Leaves must not be pruned. Normally these turn yellow anyway as the plant ages and grows, and fall off by themselves. In exceptional cases, such as leaf disease or pest infestation, they have to be removed. Root pruning can stimulate the growth of poor plants, but success is not guaranteed. When the Phalaenopsis flower are about to start withering, leave the flower stems on the plant until they are completely dried out. Only then prune them.

Regardless of whether you prune your Phalaenopsis with garden shears, a knife or a scalpel: Sterilize your tools beforehand with methylated spirits or hot water.

Propagating Phalaenopsis

The Phalaenopsis is mainly propagated by sowing or by keiki. Orchids of this genus form new plants from the shoot eyes on the pseudobulbs directly on the inflorescence stem. You can simply cut these so-called keiki and place them in a new substrate. Regular propagation keeps the plants blooming and healthy - and lets your Orchid collection grow. Sowing, on the other hand, is more for specialists and is required primarily for breeding new varieties.

In professional gardening, Phalaenopsis orchids are propagated almost exclusively by the so-called meristem culture. In specialized propagation, plants are cultivated from tiny cell clusters of the meristem tissue under laboratory conditions.

Diseases and pests

Despite their exotic origins, Phalaenospis are no more susceptible to diseases and pests as other indoor plants. A good cultivation results in plants that are very robust and resistant. Regular checks are nevertheless essential, as the Phalaenopsis can be affected by spider mites, scale insects or aphids. Mealy bugs or crab lice can also infest the plant. In the case of grey mould rot (Botrytis), a greyish-white coating covers the plant. Here you may have to resort to fungicides. In case of thunderbugs, also known as thrips, the plant has countless white dots on the underside of their leaves. If this occurs, increase the air humidity at the location. Also check the indoor plants that are in close proximity to your Phalaenopsis. Their pests, for example whiteflies like to attack the Orchids.

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