HOW TO WATER AN ORCHID...NOT. explaining root rot and overwatering,by soo neaty 8 years ago
This shows what happens with overwatering and poor drainage to the orchid potting medium. This was my friends orchid and was bought 6 months ago. She was told to water with a tablespoon of water every week, which she faithfully did. Unfortunately there was poor drainage and the moss was packed too TIGHTLY ( I have seen this with store bought orchids and have had to repot them in the same moss lightly using about half the amount of moss and then making generous drainage holes in side of the pot to allow root aeration. In the store the orchids come from greenhouses that have lots of warmth and ventilation and so in those conditions, the tight packing works. In most homes the tightly packed moss simply makes it too wet and roots rot.
Rotten roots cannot absorb water and then the plant leaves become wrinkled and dehydrated and the plant dies. Pack moss LIGHTLY and lots of drainage holes is the key.