According to Beautiful Orchid, a San Francisco, California orchid grower; many people make the mistake of assuming that since orchids are native to tropical rainforests, they must be watered several times a week. Unfortunately, watering this frequently will kill the roots of the orchid in no time.
The general rule of thumb for orchids grown in the home is to water every 5 to 12 days, depending on the type of orchid, the [ambient] temperature and the time of the year. During the summer months (June - September) when days are long and it is warm more frequent watering is required than in the cooler, shorter days (October - February).
There are three basic types of orchids, as far as watering is concerned:
- Those that should be kept evenly moist at all times;
- Those that should be allowed to nearly dry out between watering, except when in active growth;
- Those that should always be allowed to dry out a bit between watering.
The guidelines below list the watering regime of major varieties of orchid in each type.
Varieties to keep evenly moist (not soggy or wet) at all times: Paphiopedilum, Miltonia, Cymbidium, Odontoglossum,
Varieties to keep evenly moist during active growth, allowed to dry out between watering when not: Cattleya, Oncidium, Brassia, Dendrobium.
Varieties to keep nearly dry between watering: Phalaenopsis, Vanda, Ascocenda.
Note that when watering your orchids; take care to avoid wetting the leaves. If water gets trapped in between the leaves, dry them quickly using tissue or cotton ball. And, after watering, do not allow the base of the orchid pot to rest in the residual or standing water.
