Question
i have a phal orchid. i used to pot it in a very big pot. but now i pot it in a small pot just fit it. when i repot the orchid, i find the most of the root is roted, and the new root grows out to be very unhealthy, the new small root turn black and died pretty soon i don't know why. please help

Answer
Hello Kai,

From your description of what happened and is happening now, it sounds like the rotting root problem may be caused by too much water.  Phalaenopsis roots like moisture but not constant wetness around them.  The best method for watering phals is to wait until the potting media becomes barely moist between waterings, this can be from 3 days to 10 or more days depending upon the media, growing environment and weather.  

Putting it into a smaller pot will help, especially if there are some live roots left on it.  When it was in the bigger pot, the media stayed wet much longer and if you water when it is still wet, the roots die and rot.  

Hope this helps.

Jim Kawasaki
San Jose, Ca.