Did you know that household cinnamon that we sparingly use in our food recipes is also good for our orchids? I use it on my orchids, instead of commercial insecticides, because I have two dogs.
Cinnamon has fungicidal potential that will help control and prevent fungus problems from attacking the orchid plants. I use it sparingly on my plants when I notice the beginning of black rot. Cut off aggressively the beginning of the infection, being sure to remove enough leaf area to ensure no spores are left on the plant. Then sprinkle cinnamon on the cut area to entirely cover the wound. Be sure to place your injured plant in a dry area to help the wound heal.
When repotting my orchids, if a plant has poor root growth due to rotting roots, I trim off the dead roots and treat the remaining live roots with cinnamon before repotting the plant. Do not water the plant for a few days, allowing the roots to heal and recover.
Should a leaf of your plant become sunburned and the burnt area begins to fester, treat the area as you would for black rot, before it happens. If the burnt area is crisp, leave it alone, but watch it.
(Tip submitted by Ruth Chun)