Orchids come in different sizes. I have a miniature phal in a 3-inch pot. This orchid needs watering more often than the larger ones in 6″ deep pots. An orchid in a larger pot will need watering less often, but will need more water quantity wise. The material of the pot will also make a difference. Those in plastic will dry out a bit slower than those planted in porous terra cotta.
The quality of water used, whether for spraying or watering, is of great importance. Since tap water has often been chemically treated, generally with chlorine, it should be used with caution. The best water for orchids is undoubtedly rainwater. Rainwater, as it passes through the air, dissolves and absorbs many substances such as dust, pollen and other organic matter. This enriched rainwater contributes to the nourishment of the plant.
Phalaenopsis, the Moth Orchid, is one of the most commonly available and easiest to grow orchid genera. It is an especially good choice for beginners to orchid growing. They have large, showy flowers that come in a wide variety of colors. Most species have several flowers per stem, but some have more, and others have as few as one or two. There are a great many hybrid varieties on the market.

It has come to my attention that some of you have been using photos or descriptions lifted from this site to aid in selling plants. Please be advised that we do not allow this and will prosecute offenders. Any reuse of these photos for commercial gain is patently illegal. All the photos of mine and my contributors are copyrighted and we will pursue offenders vigorously!
The pseudobulb has a smooth surface with lengthwise grooves, and can have different shapes, often conical or oblong. Its size is very variable; in some small species of Bulbophyllum, it is no longer than two millimeters, while in the largest orchid in the world, Grammatophyllum speciosum (giant orchid), it can reach three meters. Some Dendrobium species have long, canelike pseudobulbs with short, rounded leaves over the whole length; some other orchids have hidden or extremely small pseudobulbs, completely included inside the leaves.
The amount of drainage your pot has will depend on the size of the pot, with larger pots requiring more drainage holes than smaller pots. Since orchids prefer to grow in smaller pots, a good rule of thumb is to make sure the pot has 4-8 holes if it’s 4 inches (10 centimeters) or so, while larger orchid pots (around 6 inches or 15 centimeters) should have 8-12 holes for drainage.

Some saprophytic orchid species of the group Gastrodia produce potato-like tubers and were consumed as food by native peoples in Australia and can be successfully cultivated, notably Gastrodia sesamoides. Wild stands of these plants can still be found in the same areas as early aboriginal settlements, such as Ku-ring-gai Chase National Park in Australia. Aboriginal peoples located the plants in habitat by observing where bandicoots had scratched in search of the tubers after detecting the plants underground by scent.[Note 1]
Catasetum orchids, along with the other members of the Catasetum alliance, have big, thick pseudobulbs with an attractive fan of thin leaves along their length. The flowers can be very showy, but are unisexual, so that male and female flowers look different. Lighting affects which kind appears. They need a dry rest after flowering when the leaves drop.
There are over 60 varieties of the Vanilla orchid, and unfortunately, it only blooms for one day, opening in the morning and closing at night. They grow in clusters of 12-20 buds, and they are yellow-green in color and reach approximately six inches in length. Just like their name suggests, you can actually get vanilla from these flowers, and the blooms have a nice vanilla scent as well. They have to be mature in order to flower, which can take two to three years, and they grow up to ten feet in height. They do best in a garden or a greenhouse, but never as an indoor plant, and they need vertical support to grow and thrive.

The Orchideae tribe is the largest tribe within the Orchidoideae subfamily, and contains a variety of flower forms. Flowers in this tribe dominate the orchid flora in the temperate Northern Hemisphere, though they can also be found in East Asia. These orchids usually have a three-lobed lip without a basal spur, prominent caudicles, and erect anthers.

If you just want a quick way to water your orchid without having to transplant the orchid, you can use the ice cube method. Put the equivalent of 1/4 cup (59 ml) of frozen water (usually about three medium ice cubes) on top of the potting mix. Make sure that the ice never comes in contact with the orchid itself - it should only touch the soil. Let the ice cubes melt into the pot. Wait about a week before you do it again. This method is not optimal for the long-term health of the orchid, so only use it as a temporary solution.[2]

Most orchids are not heavy feeders. Many orchids bloom year after year with no fertilizer at all. During active growth, when new leaves are being produced, you may fertilize every other time you water at half the strength recommended on the fertilizer package. However, it's important to deliver water without fertilizer at least once a month to flush excess fertilizer salts from the bark mix and avoid fertilizer burn to the roots. 
×