Orchids have been used in traditional medicine in an effort to treat many diseases and ailments. They have been used as a source of herbal remedies in China since 2800 BC. Gastrodia elata is one of the three orchids listed in the earliest known Chinese Materia Medica (Shennon bencaojing) (c. 100 AD). Theophrastus mentions orchids in his Enquiry into Plants (372–286 BC).
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 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.

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.

Some orchids, such as Neottia and Corallorhiza, lack chlorophyll, so are unable to photosynthesise. Instead, these species obtain energy and nutrients by parasitising soil fungi through the formation of orchid mycorrhizas. The fungi involved include those that form ectomycorrhizas with trees and other woody plants, parasites such as Armillaria, and saprotrophs.[25] These orchids are known as myco-heterotrophs, but were formerly (incorrectly) described as saprophytes as it was believed they gained their nutrition by breaking down organic matter. While only a few species are achlorophyllous holoparasites, all orchids are myco-heterotrophic during germination and seedling growth, and even photosynthetic adult plants may continue to obtain carbon from their mycorrhizal fungi.
A pollinium is a waxy mass of pollen grains held together by the glue-like alkaloid viscin, containing both cellulosic strands and mucopolysaccharides. Each pollinium is connected to a filament which can take the form of a caudicle, as in Dactylorhiza or Habenaria, or a stipe, as in Vanda. Caudicles or stipes hold the pollinia to the viscidium, a sticky pad which sticks the pollinia to the body of pollinators.
Orchids have been used in traditional medicine in an effort to treat many diseases and ailments. They have been used as a source of herbal remedies in China since 2800 BC. Gastrodia elata is one of the three orchids listed in the earliest known Chinese Materia Medica (Shennon bencaojing) (c. 100 AD). Theophrastus mentions orchids in his Enquiry into Plants (372–286 BC).
Many neotropical orchids are pollinated by male orchid bees, which visit the flowers to gather volatile chemicals they require to synthesize pheromonal attractants. Males of such species as Euglossa imperialis or Eulaema meriana have been observed to leave their territories periodically to forage for aromatic compounds, such as cineole, to synthesize pheromone for attracting and mating with females.[10][11] Each type of orchid places the pollinia on a different body part of a different species of bee, so as to enforce proper cross-pollination.

^ Guillaume Chomicki; Luc P.R. Bidel; Feng Ming; Mario Coiro; Xuan Zhang; Yaofeng Wang; Yves Baissac; Christian Jay-Allemand & Susanne S. Renner (2015). "The velamen protects photosynthetic orchid roots against UV‐B damage, and a large dated phylogeny implies multiple gains and losses of this function during the Cenozoic". New Phytologist. 205 (3): 1330–1341. doi:10.1111/nph.13106.
Check your water. For a long time, serious growers insisted that orchids could only be watered with rainwater. Nowadays, most people just use tap water, and this is fine. However, be aware that treated water may have higher salt content, and some water is high in calcium. If you see deposits forming on your plants, you should seek out a new water source.
To give you a better feel for how orchid subfamilies, tribes, and genera are interconnected, we created a compendium of popular American orchids. It plots over 100 “local” genera of orchids so you can see just how impressive and expansive this family is. You may be surprised that some of these vibrant, exotic looking orchids exist in your own backyard!  Want to learn more about flowers and plants? Check out our other compendiums featuring types of roses and types of desert plants.
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.
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If only there was an easy guide or a little water fairy that hovered over your plants and told you exactly when and how much to water. Unfortunately, there isn't. But I think this is one of the satisfying reasons we grow orchids. It's all about balance and instinct—and plenty of patience. Here are some of the factors you need to consider when developing a watering schedule:

Like most monocots, orchids generally have simple leaves with parallel veins, although some Vanilloideae have reticulate venation. Leaves may be ovate, lanceolate, or orbiculate, and very variable in size on the individual plant. Their characteristics are often diagnostic. They are normally alternate on the stem, often folded lengthwise along the centre ("plicate"), and have no stipules. Orchid leaves often have siliceous bodies called stegmata in the vascular bundle sheaths (not present in the Orchidoideae) and are fibrous.

The type genus (i.e. the genus after which the family is named) is Orchis. The genus name comes from the Ancient Greek ὄρχις (órkhis), literally meaning "testicle", because of the shape of the twin tubers in some species of Orchis.[19][20] The term "orchid" was introduced in 1845 by John Lindley in School Botany,[21] as a shortened form of Orchidaceae.[22]

I wish I could tell you exactly how often to water your phalaenopsis orchids and how much water to give them and be done with this post. Unfortunately, there is no one size fits all answer. When it comes to watering any plants there are lots of factors to consider that’ll make the amounts and regularity vary. I’ll go over all those factors so you can see what will be the best for your own situation.