What’s wrong with my orchid?
There are many reasons why buds fall off before flowering:
Under or over watering.
Temperature extremes and rapid temperature changes (heating vents, air conditioning blowing directly on the plant).
Fumes from natural gas leaks, paint, other chemicals.
Ethylene – high producers are apple, avocado, peach, pear, plum, melons, figs, and tomatoes.
Aphids, thrips and some mites.
Changing growing location. If you want to change a plant’s location so that it will be enjoyed, wait until the flower opens first.