Your Phalaenopsis requires a minimum night-time temperature of 16 °C and a maximum daytime temperature of 26 °C. A daytime temperature of 20 to 25 °C is ideal. By a temperature that is too low, the leaves will turn a reddish colour and may even die back completely if kept in the cold for a long time.
In its natural setting the Phalaenopsis grows in the trees. The plant therefore requires a lot of light, but no direct sunlight, particularly not during the summer months. Some early morning sun behind a curtain won’t do any harm (as a rule of thumb do not leave the plant in the sun for more than 10% of the time). An ideal spot is by an east-facing window. If the leaves start yellowing, this can be a sign of too much direct sunlight. But too dark is not good either: this will cause premature shedding of flowerbuds with dark green leaves. This points to a lack of light.
Do not water the pot orchid in the heart of the plant. This can cause rot and mould. Water the soil in the pot. The plant will enjoy rain water that you have collected - avoid hard tap water. Preferably water early in the day, but only if the soil in the pot feels dry and the roots look grey. Be careful of overwatering. If unsure, it’s better not to water.
In its natural setting the Phalaenopsis has 100% humidity. The higher the humidity in the room, the longer you can enjoy your plant. Ideal places are the kitchen, bathroom or even the conservatory. Spray the plant regularly and place the pot in a wide dish filled with baked clay granules or gravel and water regularly (the pot may not stand in the water). This allows the water to evaporate under the plant and creates higher humidity in the immediate vicinity of the orchid.
The most important requirement for an ideal growth medium is a good, moisture-retaining drainage. This allows the fleshy roots to breathe well and at the same time take up water. Opt for a mixture of pine bark (Pinus maritima), sphagnum moss, pumice or perlite (possibly replaced with pieces of rockwool or kapok). This is better than ordinary potting compost, which is more likely to cause root rot. Such a potting mixture can generally be bought from the better garden centres.
The soil in the pot contains little nutrition. It is therefore a good idea to feed the Phalaenopsis when you water it. Buy plant food with a nutrient content of 20-20-20, specially designed for orchids. This can be bought in both liquid and solid form from florists and garden centres. You should feed regularly at the end of the spring or the start of the summer (the growing season for the pot orchid); feed less during the winter months or when the plant is resting.
Place plants which have finished flowering in a colder spot (12°C) for a few weeks, preferably in autumn. This encourages the formation of new flowers. Cut flower stems back to three joints above the leaf. The pruning will cause new flower stems or the rare ‘keikis’ (plantlets) to emerge from these uppermost dormant nodes.
Only repot when necessary: when the soil is exhausted, every two years on average.
Use a transparant plastic pot so you can see the roots. A plastic pot has the advantage that the soil dries out more slowly.