The second type, the nobile Dendrobium, grow warm in the summer but require a cool winter period to induce flowering. They need to experience temperatures in the 40s to low 50s (preferably) in order to flower well. They are distinguished by bearing fuzzy, flat, round, colorful flowers close to stem, which cover most of the stem on a well-flowered plant.
Orchids of all types have also often been sought by collectors of both species and hybrids. Many hundreds of societies and clubs worldwide have been established. These can be small, local clubs, or larger, national organisations such as the American Orchid Society. Both serve to encourage cultivation and collection of orchids, but some go further by concentrating on conservation or research.
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.
The vast majority of orchids grown in the home are epiphytes, meaning they live in nature by clinging to trees or even stones. The roots of these plants are highly specialized organs that differ dramatically from normal plant roots. Of course, it's hard to generalize about anything when it comes to orchids. This is the single largest group of plants in the world, so for every rule, there are 100 exceptions.
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.
About 30,000 species of orchids come from all over the world, on every continent except Antarctica. As you can imagine, they come from a wide range of habitats and each type of orchid has different care requirements. Their incredible diversity also means you can always find another interesting orchid type to grow, which is one of the principal reasons the orchid hobby is so addictive!
Make sure the pot has drainage holes. You can't properly water an orchid unless it has holes through which the water can drain. Water sitting in the pot will cause the roots to rot, so it needs to be able to drain through the bottom. If you bought an orchid that came in an ornamental pot without holes, repot the orchid in one with adequate holes in the bottom. Use an orchid potting mix instead of regular potting soil.
Orchids are an incredibly unique and fascinating group of plants. Many people can identify a Phalaenopsis (moth orchid) or Cattleya (the old corsage orchids), but the question often is asked, “What makes an orchid an orchid?” Orchids have some morphological (physical) traits that make them stand out from other plant families. In orchids, many of their floral parts come in groups of three. There are three sepals, which are the outer petals; these are what you see when you look at an unopened bud. There are also three petals, but in orchids one of the petals has been specialized into a labellum, or lip. This is usually the bottommost petal, and it helps to attract the pollinator to the reproductive organ. In orchids the reproductive organ, known as the column, combines both the male and female parts in one structure.
The complex mechanisms that orchids have evolved to achieve cross-pollination were investigated by Charles Darwin and described in Fertilisation of Orchids (1862). Orchids have developed highly specialized pollination systems, thus the chances of being pollinated are often scarce, so orchid flowers usually remain receptive for very long periods, rendering unpollinated flowers long-lasting in cultivation. Most orchids deliver pollen in a single mass. Each time pollination succeeds, thousands of ovules can be fertilized.
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.
The Bulbophyllum orchid genus is the largest in the Orchidaceae family, with over 1800 species, making it the third largest genus of plants. (Taxonomists will probably eventually split it into several smaller genera, but with so many types of orchids it's a massive undertaking!) They differ widely in appearance, but all have a single leaf emerging from the top of the pseudobulb, flower stems coming from the bottom of the pseudobulb, and a hinged lip designed to tip insects against the column. Many are pollinated by flies, and stink like dung or rotting carcasses, which is a great conversation starter and gives you bragging rights for putting up with it! (They don't all stink, fortunately.) The rhizomes wander all over the place and often branch freely, so it's easy to grow an impressive specimen.