Question
"Hi there,



I own about six orchid plants - all of them have lost their petals except for one a "phalaenopsis - long pride star". I noticed last week that it had a lot of white mold growing on the back of the flower. I noticed too that the spots where petals had been along the stem also had mold growing and when I investigated the leaves it was there too. I am very nervous that this mold will contaminate my other orchids and this morning I found that another phalaenopsis had the same white mold growing out of the centre of the stem and onto the new leaves. I have never re-potted these plants since I got them - is this what I should do? If I re-pot them can I use the same pot after it has been carefully washed out or should I get a new pot. And finally, how does this awful mold begin?



Thank you for helping me save my orchids,


Answer
Hi Vanessa,

I hope I can help you save your orchids.

I'm not sure what the white mold is without actually seeing it but I suspect it might be mealybugs which are white and fuzzy looking.  To test if they are mealybugs, take a Q-tip dipped in isopropyl alcohol and touch some of the white mold areas.  If the alcohol exposes a tiny insect body, then it is mealybugs that have infested your orchids.  By the way, mealybugs especially love phalaenopsis orchids but will infest other orchids if phals. are not around.

You can try wiping the leaves to get rid of the mealybugs on them but I'm afraid there are many more nesting within the pot waiting their turn to come out.  The best way to take care of them is to unpot the orchids, remove all potting media from the roots, dip or spray the entire plant including the roots with alcohol, wipe the leaves and roots to clean them of mealies, repot using new fresh potting media in new pots.  You could reuse the current pots after thoroughly cleaning them with soap and water.  

By the way, mealybugs will slowly suck the life out of your phals.  You may already have noticed the heavily infested leaves are beginning to curl around the edges and looking a little dry.  

To prevent mealies from infesting your orchids in the future, go to your local garden center and ask for a systemic insecticide safe for orchids.  Be sure to follow the directions along with how to safely handle it.  Treat your orchids twice a year, once in the spring and again in the fall.  

Hope this helps save your orchids.  

Jim Kawasaki
San Jose, Ca.