Question
I have a Phalaenopsis orchid that has developed some white/black mold on the
outside of the pot and on some of the potting soil/chips.  Is this harmful to the
plant or myself?  Is there any way or need to remove it?  Thanks!

Answer
Hello Colleen,

Black mold developing on the pot and potting chips is an indication that you are keeping it too wet.  While it is fairly easy to remove the mold from the pot by wiping it with a paper towel and bleach, removing it from the potting chips is best done by replacing the chips with fresh potting chips.  

As for the white appearing mold, I believe it may be a salt build up.  Salt may be from your water supply (hard water) or from excess fertilizer salts or both.  

To remedy both conditions, repot the phalaenopsis into fresh potting chips.  Remove any soft mushy roots while repotting as they are dead.  It is best to wait until the potting chips become barely moist before watering again, this will help prevent or minimize mold.  

Hope this has helped.  

Jim Kawasaki
San Jose, Ca.