Water thoroughly. When you do water, do it like you mean it. Different growers have different rules, but many professional growers turn on their sprinklers for 8 or more minutes. Successful home-growers sometimes dunk their plants, pots and all, into a bucket or sink of water. Some varieties, such as vandas, can be left floating in water for a surprisingly long time. The idea is to make sure the velamen is completely saturated. You want tiny droplets hanging on the roots after watering. This means the plant is completely hydrated.
The Neottieae tribe consists of 3 genera. It is distributed throughout the world including Europe, tropical Africa, Sri Lanka, Southeast Asia, China, Japan, New Guinea, and Australia. In the Western Hemisphere, it is found in the western United States, Central America, and South America. They have fleshy, but slender roots, and thrive in temperate habitats.
Some orchids have water-storing organs, and some do not. If you have a type of orchid that has the ability to store water, such as cattleyas or oncidiums, you should allow the orchid to completely dry out before watering. If you have a type of orchid that does not have water-storing organs, such as phalaenopsis or paphiopedilums, you should water the orchid before it is entirely dry.
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.
Some orchids mainly or totally rely on self-pollination, especially in colder regions where pollinators are particularly rare. The caudicles may dry up if the flower has not been visited by any pollinator, and the pollinia then fall directly on the stigma. Otherwise, the anther may rotate and then enter the stigma cavity of the flower (as in Holcoglossum amesianum).
The Cypripedioideae subfamily is known for its lady slipper orchids, which are named after their slipper-shaped pouches that trap insects and help the flowers get pollinated. There are 5 genera in this subfamily: Cypripedium, Mexipedium, Paphiopedilum, Phragmipedium, and Selenipedium. Cypripedioideae orchids have two lateral, fertile anthers, which is unusual in most other orchids.
Almost all of the preceding orchids were found near these two landscape shots, # 1 shows the cleared forests which has grown back with pine in the background and the original scrub forest with rock outcroppings in the foreground. The orchid not blooming is a Masdevallia, the bloom spike I do not think is from an orchid. Anyone? #2 Shows the stunted bushes that grow amid rock outcroppings on a hill on the sides of the savannah of Bogata'.
Orchid roots are surrounded by a tissue-paper thin membrane called velamen. This multi-purpose membrane soaks up large amounts of water quickly, adheres to rough surfaces, and promotes the exchange of minerals and salts. Like an expensive water meter, orchid velamen is an excellent indicator of your plant's water needs. Dry velamen is white or silvery, and freshly watered velamen is green or mottled (depending on the species).
The type of potting medium being used can also affect your plant's water requirements. Bark has a tendency to dry out more rapidly than sphagnum moss, for instance. It is important to remember, however, that even when the surface of your pot is dry, the root area may remain moist. Poke your finger or a regular wooden pencil an inch into the pot; if it feels moist to the touch or if the pencil looks moist, do not add additional water. The potting medium should always be damp, but not soggy—neither should it be allowed to get extremely dry.
I can control the chances of overwatering by taking them to the sink and letting the water all drain out. That’s the way they get watered in nature as they’re growing on other plants and rocks and those showers blow through. Second, these are tropical plants which like cozy conditions when it comes to temperature. I can’t image they like frozen water melting into them!
Consider your climate. The frequency with which you water orchids is affected by the level of humidity in your climate, as well as the amount of sun the orchid gets and the temperature of the air. Since these factors vary according to region and household, there's no rule for how often to water an orchid. You'll have to develop a routine catered to your specific environment.
Below are orchid species listed alphabetically, you can go from species to species by scrolling to the top or bottom of any page to find another alphabet bar such as this one below. All names are listed alphabetically including synonyms, so if you see your plant name without a link, there will be a reference there to procede to the name that is on this list with a link to the picture as well as cultural information for your species.
Always water early in the day so that your orchids dry out by nighttime. The proper frequency of watering will depend on the climatic conditions where you live. In general, water once a week during the winter and twice a week when the weather turns warm and dry. The size of your orchid container also helps determine how often you need to water, regardless of climate conditions. Typically, a 6-inch pot needs water every 7 days and a 4-inch pot needs water every 5 to 6 days.