If you happen to be one of those people that just have to buy the "orphans" at bargain sales that are laying around half dead, please understand what you are doing.
The plant has undergone a lot: over-watering, under-watering, too much heat, too much cold, and heavens knows what else. Saving these "orphans" can sometimes be done, but taking them to a dry home and expecting miracles is not reality. Most often it will require the intensive care environment of a well-controlled greenhouse to save the plant.
It can take years for a plant to recover to the point of producing new flowers or even new growth.
Check and see how firm the plant is in the pot, if it is shaky and not firm then chances are it is either been recently repotted or it has a bad root system. If it has been recently repotted check the mix, you may want to replace it for something more suitable for orchids, even if the plant is in bloom. Sphagnum moss is often used to pot the orchids in for shipping and if it it packed to tightly in the pot it can cause problems. Sometimes the mix can rot your roots very quickly since it does not dry out.
The pseudobulbs should be fat and plump. Beware of the shriveled pseudobulbs.
The leaves should be firm. Leaves that are limp or crinkled like an according are indications that the plant may have been exposed to excessively cold temperatures or lack of water due to no root system or just not being watered correctly.
Are the leaves brown or have spots? This is an indication of exposure to excessive sunlight or high temperatures. On many of the orchids make sure the center leaf is still growing and there is not damage to the crown of the orchid. This damage can result in crown rot and the orchid will die.
Is the foliage damaged? Look under the paper wrapper if it is covering any part of the plant.
Are the plants water logged or swimming in water inside of the paper wrapper? The pretty paper does not have drainage holes. Remove this immediately after you get your orchid home.
Is there a sticky substance on the leaves? The plant has bugs! Avoid bug-infested plants.
Are the flowers limp or the buds turning yellow? Are there buds missing? The plant has been stressed too much and will most likely drop all its flowers and buds within a few days no matter what you do for the plant.
Does the plant have a correct label? The label should say more than just "ORCHID PLANT."
Does the sales person know anything about the orchids and can they give you some information about caring for it?
Now don't get me wrong, there are some beautiful plants available and if you are careful, and know what to look for, you can find good prices and plants. But you need to be aware of what to look for. Oncidiums: Gower Ramsey and Sharry Baby with its reddish brown flowers and strong fragrance.
Phalaenopsis: Also known as "Moth orchids" with their graceful arches of blooms.
Dendrobium nobile and Dendrobium phalaenopsis type hybrids: the nobiles will have flowers growing right out of the pseudobulb (stock) and D. phalaenopsis (D. bigibbum Lindley (1852.))have long, in certain cases even branching inflorescences.
Colmanara Wildcat hybrids:
This newcomer has beautiful exotic patterns on the flowers of red, browns, white and yellows.
Cattleya, and Cymbidums: Seen at different times of the year.
Vandas and Ascofinetia: These hybrids are the orchids with the bright purple, red, and orange blooms
Let's repeat here that when shopping, remember that a bargain is not always a bargain. Orchids are not like your common houseplant and should never be considered to be in the same category.
If you want to be sure of what you are purchasing, and to have years of satisfaction from your orchid, I would strongly suggest you purchase your orchids from reputable orchid growers.
Not only do they know how to grow and ship orchids; they can also give you help in choosing the right orchid for your environment.