There are over 60 varieties of the Vanilla orchid, and unfortunately, it only blooms for one day, opening in the morning and closing at night. They grow in clusters of 12-20 buds, and they are yellow-green in color and reach approximately six inches in length. Just like their name suggests, you can actually get vanilla from these flowers, and the blooms have a nice vanilla scent as well. They have to be mature in order to flower, which can take two to three years, and they grow up to ten feet in height. They do best in a garden or a greenhouse, but never as an indoor plant, and they need vertical support to grow and thrive.
Disa is a genus of beautiful plants with rather triangular flowers, often red. They require VERY different care than other types of orchids, so it's easy to kill them if you don't know what you're doing. In particular, they like it wet and should never dry out. The best-known Disa is Disa uniflora, which in South Africa is known as the Pride of Table Mountain.
Water your orchid early in the morning. This insures complete water evaporation on the foliage as well as the crown by nightfall. If your home is very warm or has low humidity you will most likely need to water more often. The best place to water your plant is in the kitchen sink. Use lukewarm water (do not use salt softened or distilled water) and water your plant for about 15 seconds and be sure to thoroughly wet the media. Then allow the plant to drain for about 15 minutes. It may appear dry but it has had enough water. After the plants are watered, they should be placed so that the pots do not stand in water. Some people like to place the pots on "humidity trays" or in trays or saucers of gravel or pebbles and water. The pot is placed on the pebbles above the water line. This helps to insure that the base of the pot is not immersed in water, increases humidity for the plant, and provides some air circulation under the pot.
Cymbidium carry tall stems with many flowers that have a more typical orchid shape. They are easily identified by their grassy leaves, and they readily form large clumps. Most common are the cool-flowering types, which need to experience a cooler winter (nights in the 40s for some time in the fall) in order to initiate flowering. Once the flowers open, they can last for up to two months or more, especially in a cool environment. These are very showy and rewarding plants, and a plant in a six-inch pot can carry three stems with 15 or more flowers each, depending on the type.