Orchid bloom cycles depend largely on three factors that, when met and kept in balance, provide the optimal conditions for flowering. Orchids need bright, indirect light to flower, along with high ambient humidity. The third factor is especially critical and requires that there be a sharp differentiation between day and overnight ambient temperatures. While ideal specific day and night temperatures vary by species, the difference between day and night temperatures must remain substantial. Orchids typically rebloom under ideal conditions roughly once a year.
Select a growing location for your orchid that affords the plant daily bright indirect light from a southern, eastern or western exposure. Direct sunlight can be tolerated if it is either morning or late afternoon light and avoids the strongest midday sunlight. If direct sunlight is applied ensure that there is fresh air flow and temperatures do not rise above 90 degrees, which can quickly desiccate and kill the orchid.
Provide ambient temperatures that are ideal for your species of orchid which will fall between roughly 50 and 80-degrees Fahrenheit. Consult the tag on your orchid plant to determine the optimal temperature range. To encourage re-bloom ensure that there is at least a 10 to 15-degree difference between day and night temperatures every day throughout the year.
Create an environment for your orchid with optimal humidity levels to enhance flowering. In addition to regular weekly watering, raise the ambient humidity around the orchid as consistently as possible to a 50% level. Create a homemade humidity tray filled with pebbles and water placing the orchid pot on top and refilling the water as it evaporates. In addition to the tray, mist the plants with tepid water once or twice daily. Alternatively, as a lower maintenance option, use a cool mist humidifier near where the orchids grow.