I noticed some questions about orchid care, and rather than posting in all of the threads, I figured a single post in a new thread may be a better option.
Hope its ok if I do this
Most orchids are "air" plants, although there are some terrestrial varieties.
For terrestrial varieties, planting in the ground is best as the soil in the ground stays moist longer than the soil in pots.
If potted terrestrials are preferred, any composted potting soil will do nicely, and should be watered until soil is moist all the way down, then allowed to mostly dry out before the next soaking. Can also be sprinkled each day rather than being soaked, but most people are too busy to sprinkle every day.
Terrestrials will grow up to 3 feet tall and generally put out 2 or 3 flower stems at a time, a couple of times a year.
Arboreal orchids are different though.
They grow on trees in the wild, their roots wrapping around the branch they are on.
Most nurseries will sell them in plastic pots with orchid bark in an attempt to simulate their natural preferred growth habit of being in a tree.
When purchasing an orchid in a plastic pot, choose ones that have healthy green and white roots on top of the bark, leaves with no dark or black spots or rust spots, and flowers that you enjoy looking at.
Take it home, keep it in a bright window out of direct sunlight and water it once a week until the flowers fade.
Once the flowers fade, find a piece of hard wood with crevases or depressions in it, oak, teak, and redwood are hard woods and will generally last for the life of your orchid.
Slice the wood down the length to make two pieces with flat bottoms, then chunk those pieces up into 8 to 10 inch widths.
Each piece is a good mount for a single orchid, do not mount more than one orchid on the same piece of wood as one will overtake the other.
For draping orchids (varieties that prefer to hang down) drill a hole in the wood to insert a hangar into so that it can be hung up like other hanging plants.
It should be noted that as arboreal plants, most orchids actually prefer to be hung up rather than stood, but many are fine with standing and can be assisted in standing by wiring the stems together or to a bamboo stick (not tightly though).
Remove the orchid from the plastic pot and remove as much of the orchid bark as you can without harming any of the live roots.
The brown roots attached to the bark are dead and can be cut off.
Using florists wire, mount the orchid on the wood in a depression or crevasse so that it is secure and does not wobble.
Stand or hang your mounted orchid in a bright place indoors or outside (during warmer weather) but not in direct sunlight. Under trees is excellent as it is their naturally preferred location, but on a covered patio is fine too.
Sprinkle the roots and the wood every day or every other day with filtered water, just enough to moisten the roots. They will dry out by the next day because there is nothing holding the water in.
They do not have to be moist all the time, and if kept moist all the time, the roots will rot, so it is best to allow them to dry before sprinkling again. Think of it as rain simulation.
In warmer climates orchids love to be out in the rain, and cloud covered light is ok, just be sure to bring them back in when the sun comes back out
Arboreal orchids grow new stems that are longer than the old stems, the smallest stems were the baby plant, the next longest stems were the teenage plant, the longest is the adult plant, the newest is the granny plant, etc. so the old stems will not get any larger than they already are, do not be concerned that they are not growing.
It is best to leave the old stems on the plant as they provide energy to the plant as long as they are green, even after all the leaves have fallen off.
Only remove old stems when they are no longer alive (dry and brown).
Various orchids bloom at various times, usually once or twice a year, but there are some varieties that will bloom 3 or 4 times a year, and even some that will bloom almost constantly.
To have an orchid blooming all the time, purchace one each week or two for a year, they will rotate through bloom just as you bought them.
If you want to feed your orchids, use a weak mixture of water soluable orchid fertilizer once a month or so, but as air plants, orchids dont really require fertilizing and will do just fine without it.
Old leaves will turn lemon yellow and drop off, sunburned leaves will appear yellow on the surface. If your orchid has leaves that are yellowing on the surface but not on the underside, it is getting too much sun.
If your orchid develops any kind of unusual spots, keep it away from your other orchids.
You can spray it with a mixture of rubbing alcohol and water to kill any parasites.
If you find rust colored spots, they are probably rust mites, and the spots can be scraped off with a butter knife, then spray with the alcohol to kill any that were missed.
Keep the plant quarantined until it has been disease free for a year.
Other than these things, orchids dont like to be fussed with much, and do best when located in their happy place and ignored except for sprinkles.
I hope all this information helps