Bacterial Infection

[Orchid Whisperer]

Not all black spots are bacterial. Here is a guide to help you determine whether you have a fungal or bacterial disease: Orchid Diseases

Here is a guide to selecting the right treatment for a specific disease: http://www.staugorchidsociety.org/PD...idDiseases.pdf

Finally, some black spotting may be due to environmental or cultural problems: Orchid Environmental Damage

The Listerine may help until you can acquire the right treatment for the disease your plants have, or give you some peace of mind until environmental problems can be corrected.