Most orchid varieties grow well in the same indoor temperature as other houseplants. A daytime high in the 70s or warmer and a nighttime low between 55 and 65 degrees suits orchids well. It is not a good idea to have orchids sitting next to windows on very cold nights, as the plants can suffer cold damage. As a solution, you could place a piece of cardboard between the plant and the window as a means of insulation from cold.
The ideal light for orchids is indirect sunlight all day long. Placing plants 1 to 3 feet away from a south-facing window is generally recommended. Many orchids gardeners like to move their plants into an outdoor shade area for the summer. The plants also grow and bloom well under fluorescent light. The minimum artificial-light can be fulfilled with a couple of 36- to 48-inch shop lights with forty-watt regular bulbs placed six inches above the plants. Artificial lighting needs to be kept on for at least 12 hours during the day. Plants that receive a combination of artificial and natural light tend to bloom better.
Watering is one of the most critical aspects of orchid care. If over-watered, the plants will die. Orchid plants have thick fleshy roots, which require very good drainage. This is the reason why orchids are grown in special potting mediums that contain either fibers of the osmunda fern or fir bark. Generally, orchids need watering only once a week. If the plants are grown in clay pots they might require more frequent watering. Make sure the potting mix is slightly dry before the next watering. When watering, make sure the water runs out of the drainage holes at the bottom.
Orchids are a native of the tropics and thrive in moist, humid air. Many homes are often too dry for optimal orchid growth. This is especially so in the winter. The best way to increase humidity is to place the pots on pebbles in a tray or saucer with water. As the water evaporates, it continually maintains a humid environment for the plants. Do not place the pot in the water but make sure it remains elevated by being placed on the pebbles. Decorative rocks are often used to create a more unique effect. Humidity can also be improved by misting the plants with distilled water.