Orchids in general like quite a lot of water but cannot stand "wet feet". Most orchids have roots designed to be exposed to air and to dry out between watering. Use heavy amounts of water that really flush out the pots. Then do not water again until slightly damp all through the potting material. Frequency of watering depends on pot size, type of potting material, amount of light, ventilation, humidity in their particular growing place and conditions.

Watering in bark mixes which include redwood fiber and peat moss is a much more critical matter and should be done very carefully to avoid rotting off roots and turning the mix sour. Water heavily at first, then by care-observation, water again only when material becomes dry a considerable distance down in the pot. Water only enough to dampen the material and watch out that you do not keep it soggy wet, particularly in the bottom of the pot.

Deciduous types should not be watered when completely leafless. Stop watering when leaves yellow and start to drop. Resume watering as soon as new growth starts.

Most commonly grown tropical orchids fall into 3 general categories of temperature requirements:

Cool - Day 55 to 70º, Night 45º

Intermediate - Day 60 to 75º, Night 50 to 60º

Warm - Day 60 to 80º, Night 55 to 70º

These categories are only general and many orchids do well in two of the three categories. Individual plants of many types will often do better in the next warmer category than listed.

Food and light go together in orchid culture, as the plants can use more food when given more light. If the foliage of the plant is yellowish, it needs more food. If lush dark green, it needs more light. The proper balance of food and light gives a medium grass-green color for foliage of most orchids. In general, orchids will grow strongly and flower best if given as much light as possible without burning the leaves. This will vary according to the season and the light intensity in your locality.

Feeding should be increased when plants are in active growth, at least once a week during the growing season, then reduced slightly when not in active growth. Most growers use a soluble, hydroponic plant food in the water that they water with. Occasional waterings with plain water will leach out any accumulation of salt in the potting material, but regular and often feeding will keep a constant supply of food available to the plant for optimum results.

Seedlings in general need somewhat more shade than larger plants, which should be gradually reduced as they approach maturity.

There are two good times to repot. The best is just as new seasonal root growth starts, so that the plant becomes re-established in the new material as soon as possible with as little resulting setback as possible. Careful observation of the individual plants will show you when as different ones start roots at different times in their growth cycle; some start new roots just as the new growth starts - others start roots when new growth is about half formed, and still others only after their new growth is completed.

The next best time to repot is during the dormant cycle after flowering and just before, or as the new growth starts.

In general, it is best to disturb the roots as little as possible in repotting, but all old dead roots and deteriorated potting material should be removed every time you repot.

When changing from one potting material to another, all the old material should be removed even at the cost of losing many of the roots.

Seedlings should be potted up to next larger size regularly and often. If left too long in too-small pot, growth slows down and permanent stunting may occur.

Many different potting materials are used successfully in orchid culture and each has its advantages and disadvantages. Most orchids will do well in any of these if growing conditions and culture are varied to fit the one being used. It is usually best, however, to pick out one type for your collection and stick to it. Nothing is more difficult than trying to maintain a collection in a variety of potting materials with widely varying needs for watering and feeding.

For controlled conditions under glass with good ventilation and relatively low humidity, either osmunda fiber or any of the various fir and redwood bark mixes are very good, but watering must be carefully controlled.

For outdoor, garden or lathhouse conditions where humidity is high and watering is uncontrolled, or for people who like to water heavily and often, then either treefern (hapuu), or one of the coarse, inorganic potting materials such as slate, broken tile or brick, or very coarse bark, without finer additives, would be best.