Commonly known as the moth orchid, most of the Phalaenopsis (fal-en-OP-sis) purchased today are hybrids descended from species originating in the Asian jungles of Malaysia, Indonesia and stretching to Northern Australia. 

The ultimate house plant, Phalaenopsis are easy to grow in centrally heated homes and flower for an incredibly long time: Expect 10 weeks but don’t be surprised if your plant is still flowering after 6 months!

Phalaenopsis have fleshy oval leaves that form a crown at the base of the plant and thick silvery aerial roots. A healthy plant may only have 4 or 5 leaves; these are used by the plant to store nutrients and it is common for the plant to lose 1 or 2 old leaves and to replace them with new leaves each year.

The flower spikes shoot from between the leaves.  Plants can produce multiple spikes; each one may hold many flowers depending on the size and quality of the plant.  They do not have a flowering season as such and flowers may occur at anytime of year.  Care should be taken however with plants purchased or flowering during the winter as they will be more prone to cold drafts, weather changes and lower light levels, any of which can cause the buds to drop off prematurely or the flowers to wilt.

In their native habitat they are epiphytes which means they cling onto other plants or rocks rather than grow in soil – They are NOT parasites.  As houseplants they are sold in clear plastic pots allowing light to get to their roots and potted in special orchid compost which is very free draining.

Doritis and Doritaenopsis are close relatives to the Phalaenopsis and can be treated in the same manner.

Temperature:  Phalaenopsis require a constant warm environment, (similar to us,) which is why they make such good houseplants.  A minimum nighttime temperature of 18°C and a daytime temperature of 20-24°C are ideal.  But mature, established plants would be able to cope with temperatures as low as 15°C and all plants should be able to cope with temperatures as high as 32°C for short periods. 

Note:  To help prevent flower and bud drop, keep plants away from drafts, radiators and other heat sources.

Light:  Phalaenopsis naturally grow in the tropical jungles under very shady leaf canopies, so they grow best with good light but not direct sunlight as this can scorch the leaves.  Too much light may cause the leaves to go dark and show a red pigmentation.

Water:  Like other orchids, it is important to take care when watering Phalaenopsis.  Never over water or allow the plant to become waterlogged.  As a general rule, water once a week during the summer and once every ten days during the winter.  Phalaenopsis, as with most orchids, do not like to stand in water.  Always water well, from the top of the pot and allow excess water to drain away.  Take care not to let water sit in the crown of the plant, (where the leaves join at the centre), as this can very quickly cause crown-rot and kill the entire plant.  Wait until the plant is on the point of drying out and the pot feels light before giving the plant another good watering.  [Tip:  Check the roots through the pot.  If they are green the plant has enough water, if they are silvery and the pot feels light it needs watering.]  Clean rainwater is preferred by the plant but you can use filtered tap water.  Try to water with tepid or room temperature water.  

NOTE:  NEVER STAND THE PLANT IN WATER OR ALLOW THE PLANT TO BECOME WATERLOGGED.  This will cause the roots to rot and kill the plant.

Feed:  We recommend feeding regularly throughout the year every other watering with a balanced orchid feed, such as Ivens Orchids’ Orchid Feed.  Do not be tempted to use a strong solution of feed; little and often is the rule.  The plants may also benefit from an occasional flushing through of fresh water to remove any accumulating salts from the compost.

Air Humidity:  Good ventilation (not drafts) and moist air is essential.  The humidity can be raised by placing the plant on a tray of moist gravel or pebbles.  50-70% humidity is ideal.

After Flowering:  As the flowers start to fade, the flowering stem or spike can be cut off between the 2^nd and 3^rd node from the base of the plant; this may encourage the plant to re-flower from that spike.  Alternatively, you can cut the old flowering stems back to the base of the plant when the flowers “go over” and this may encourage the plant to produce new flower spikes.

Repotting:  Compost seldom remains in good condition for more than two years and, like most orchids, Phalaenopsis benefit from repotting regularly.  Repotting should be carried out after flowering and as the new roots develop; ideally during the spring and early summer.  It is not always necessary to pot on to a larger pot, in fact, most of the time you are only replenishing the compost and the plant will happily stay in the same sized pot for many years.  Only use a larger pot if it’s impossible to get your plant back into the same size pot.  Most Phalaenopsis look best in 12cm pots and they very rarely need a pot larger than 15cm.  Use a clear pot and good quality orchid compost such as Ivens Orchids’ General Purpose Compost.  

Basic Repotting Technique:  Tap the plant out of its old pot and inspect the condition of the root-ball.  Shake off old compost and remove all the dead, soft or black roots; these are easily trimmed using clean sharp scissors.  If you have several plants to re-pot, dip the scissors in a weak bleach solution between plants to prevent possible cross contamination.  Using a clean clear pot, support the plant in the centre of the pot while you feed fresh orchid compost around the root-ball; tap the pot gently as you continue to feed in compost.  Do not pack the compost in too firmly, as these plants prefer a free draining pot.  Always dampen down the compost before potting and only water sparingly for the first 2 weeks after repotting.

Pests:  Prevention is always better than cure so look for good healthy plants to start with and keep them that way with a clean environment for your plants.  Throw away old, weak or infested houseplants and maintain good housekeeping in the greenhouse.  Most often seen pests are scale insect and mealy bug.  Both will weaken the plant if left unchecked.  If found early enough, they may be cleaned off with soapy water or a cotton bud dipped in a small amount of methylated spirit, otherwise treat with a specific systemic insecticide.

Buying Tips:  Always buy good quality orchids from a reputable supplier and look for clean healthy plants.  If buying plants in flower, check the flowers are not damaged or that the pollen caps are still in place; if these get knocked off by poor handling or contaminated by poor storage or transport conditions, the flowers will very quickly discolor or “go over”.  Unless you have ideal transportation and growing conditions, buying a plant with immature buds may be a mistake as some plants can be sensitive to being moved during the early stages of flower development.  Look for plants whose flower buds look quite plump and ready to open.  Don’t be afraid to buy a plant whose flowers are nearly all out, especially during the winter months or cooler times of year.

Handy Hints:  Keep your plants clean and healthy by occasionally cleaning the leaves with a mixture of 1 tablespoon of olive oil and a few drops of washing up liquid mixed in about 300ml of warm water.  Use a sponge cloth to wipe over the leaves with the mixture. 

Special Notes:  Phalaenopsis are not easy to propagate but sometimes a plant may produce leaves on a flower spike instead of a flower.  If left, this may produce roots and develop into a small plant which can then be potted up.  This is called a Keiki.

 If you have a plant that has not flowered for some time it may be that a shock will encourage it to flower.  Try moving the plant to a warmer or cooler position for a few weeks or try repotting.