First thing to do is check the lighting. Orchids like to be in filtered easterly sunlight whenever possible. If your plants aren’t near a window, try bring them closer and partially close the shade. Or, if you plants are in direct light pull them away from it – if the edges of the leaves are brown or yellow that is an indication of burning, meaning too much light. Let plant sit for 2 weeks in new location before trying a new position.
Next, take stock of the soil moisture. Orchids like to be slightly damp, but not soaked. Your plants might not be blooming because they have been over watered. Try to keep watering to a half cup of water every week and half. Also, if your plant came in a decorative pot, pull the inner plastic planter out from inside to make sure moisture isn’t being retained in the decorative pot and soaking the roots. If this is the case, let the plant completely try out before watering again.
Be sure to monitor the air temperature and humidity. Orchids like slightly humid air that is kept between 50 and 80 degrees. If your plants are near a window, check for a cold draft. If they are near a heater, check the amount of heat they are receiving.
If worse comes to worse, consider tricking the plant. Some flower experts claim that if you make the plant think it is going to die, it will bloom as a swan song effort to get its genes out there one last time. This would include not watering the plant for a lengthy period of time, keeping it in the dark, and in a place that is too hot or cold for its liking. The theory is it will bloom at the last minute. Not only is this method cruel to your plant, it is also risky, as you could deprive it to a point where it can’t be revived. Use this last tactic with caution!