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.
If you are growing your orchid in tree bark or another well-draining medium, you should provide copious amounts of water to soak the roots. After soaking the potting mixture well, allow the excess water to drain out of the pot. This will ensure the return of that all-important airflow to the roots as well as flushing the growing medium to prevent the buildup of mineral salts. Just be sure that you never leave the roots soaking for more than about 15 minutes, as they will start to become waterlogged if you do.
Orchid stems are also specialized into what are called pseudobulbs. These are basically expanded stems that allow the plant to store excess water and food. The roots of epiphytic (tree-dwelling) orchids have a special outer layer of dead cells called velamen. Because orchids metabolize slowly in order to not outpace their resources, the roots also absorb slowly, meaning that they need help catching water as it passes by. The velamen cells catch and fill with water as it passes by so that the true root (the core of the root structure) has ample time to access as much water as it can. Velamen is silver-white in color, but becomes transparent when wet, so that when the root is wet it turns green as you are able to see through to the inner structures of the root that contain chlorophyll.
Orchid roots are surrounded by a tissue-paper thin membrane called velamen. This multi-purpose membrane soaks up large amounts of water quickly, adheres to rough surfaces, and promotes the exchange of minerals and salts. Like an expensive water meter, orchid velamen is an excellent indicator of your plant's water needs. Dry velamen is white or silvery, and freshly watered velamen is green or mottled (depending on the species).
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.

Anguloa, the Tulip Orchid, is well described by its common name! They have substantial, tulip-shaped flowers in shades of white, green, yellow, and red. They like a lot of humidity, intermediate-to-bright light, and cool-to-intermediate temperatures. They really like humidity and hate drying out during the growing season, but most need a dry rest after flowering.
Most orchids are not heavy feeders. Many orchids bloom year after year with no fertilizer at all. During active growth, when new leaves are being produced, you may fertilize every other time you water at half the strength recommended on the fertilizer package. However, it's important to deliver water without fertilizer at least once a month to flush excess fertilizer salts from the bark mix and avoid fertilizer burn to the roots.