Caring for orchids is all about reproducing their natural habitats. Orchids come from every continent except Antarctica, so there are a wide range of possible climates to imitate! Different types of orchids have different needs for light, water, temeratures, humidity, and other factors, so you'll have to research the particular plants you intend to grow. I'll talk about general approaches to caring for orchids below. Beginners should see growing orchids for beginners, too.
Prosthecheatrulla, formerly known as Encyclialancifolia
Tropical Orchids
Most tropical orchids are epiphytes, or air plants, which grow on the bark of trees or other plants. Many are lithophytes, growing on rocks, and a few are terrestrial, growing in the ground (or often the leaf litter on a jungle floor, rather than dirt per se.) So most tropical orchids will not appreciate being grown in soil! See the orchid potting mix page for details.
Most tropical orchids appreciate a temperature drop at night of 10-15° (6-8C), but daytime temperature requirements vary widely. Orchids that grow high in the Andes need much cooler temperatures than plants from most parts of southeast Asia! Look in the types of orchids section to find temperature requirements for many common orchid genera. Most tropical orchids fall into three general temperature categories:
Warm-growing orchids like daytime temperatures in the upper 70's to lower 80's Fahrenheit (24-29C)
Intermediate-growing orchids like daytime temperatures in the lower- to mid-70's Fahrenheit (21-25C)
Cool-growing orchids generally want temperatures to remain below 70°F (21C)
If you live in a temperate climate, you'll need to grow orchids indoors on a windowsill, in a greenhouse, or under lights in a specially-designed habitat within your home (often in a basement.)
Epiphytic orchids, since they're not growing in soil, can be vulnerable to drying out. Many have pseudobulbs, thickened stems that store water. Most appreciate significant humidity; this should usually be above 50%, usually about 70%, and even higher for plants from cloud forests, such as most pleurothallid orchids (which often like humidity as high as 100%!) In many homes, providing enough humidity to care for orchids effectively is difficult; you can mist the plants daily with a spray bottle, or make a humidity tray: fill a tray with a couple inches of gravel, set your plants on top, and add water to just below the top of the gravel, not letting the plants sit in water. Evaporation will increase the humidity somewhat.
Depending on their habitat of origin, orchids tend to prefer to be watered either as they approach dryness, or shortly after their potting mix dries out. As a general rule, orchids with conspicuous pseudobulbs or thickened leaves tend to come from drier habitats and appreciate drying out fully between waterings. Plants without pseudobulbs and with thin leaves tend to like to be watered when they are approaching dryness. Overwatering kills far more orchids than underwatering, as keeping the potting mix too wet deprives the roots of oxygen, causes them to rot, and also breaks down most potting mixes, exacerbating both problems. Overwatering is a very common mistake in caring for orchids, even among experienced growers. Orchids should generally NEVER be set in water, with just a few exceptions, such as Disa orchids and many Phragmipediums, which appreciate a lot of water, often growing by streambeds in nature.
To water orchids, run water through the pot, trying to get all of the potting mix wet, until water runs out the bottom of the pot. (Take it to a sink first, unless you're growing orchids in a greenhouse!) To fertilize orchids, mix a fertilizer into the water. There are many fertilizers on the market formulated specifically to help with caring for orchids.
Some orchids need a "dry season" sometime during the year, usually shortly after flowering. They'll drop all their leaves and not want to be watered until they start growing again. Otherwise, after bloom care for orchids is the same as care at any other time. (Though you'll want to trim off the old flower spike if it's turned brown. Trimming and pruning orchids to remove dead flower stems, leaves, and so forth is a good idea when caring for orchids of all types, provided you use sterile cutting tools.)
Epiphytic orchids in the wild often use their position on top of other plants to compete for light, so orchids tend to like a lot of light compared to most indoor plants. However, most do NOT appreciate direct sunlight. Orchids' preferred lighting levels are generally divided into three broad categories:
High lighting, about 3,000-5,000 footcandles, can usually be found at unshaded south-facing windows (in the northern hemisphere.)
Intermediate lighting (about 2,000 footcandles, or 20,000lux)
Low lighting, about 1,000 footcandles is common for shaded windows, or east-facing windows.
West-facing windows often get too hot in the afternoon, but are otherwise similar to east-facing windows light-wise.
Orchids with thick, vertical leaves tend to appreciate higher light, while those with thin, horizontal leaves tend to like lower light. As a general rule, when caring for orchids give them as much light as they can tolerate without sunburn. When the lighting is a lot, leaves will become paler or reddish, when it's dim they'll be deeper green. Plants will sometimes grow larger, more horizontal leaves in lower lighting conditions.
You can provide artificial lighting to orchids, and many people care for orchids by growing them under lights, often in a specially climate-controlled room (frequently in a basement.) The new LED grow lights are an especially good choice, though metal halide grow lights, high pressure sodium grow lights, and fluorescent grow lights are also popular.
Many people also grow orchids outdoors, at least during the summer.
Another way to grow orchids is in a glass container called a Wardian case or orchidarium. This makes providing the right humidity easy, and can provide additional opportunities for temperature control.
Temperate Orchids
Orchids from temperate regions can be grown outdoors year-round if you live in a suitable climate, perhaps even as part of your flower garden design as most of them are terrestrial! If you live in the right area, this makes caring for orchids really easy! You can also grow them indoors in pots, putting them in a colder place such as a refrigerator or freezer in "winter". I have a special page about how to grow cold hardy orchids, and talk about about specific types of orchids on their own pages.
To learn more about caring for orchids, browse the sections below:
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