I have been told not to let fall leaves collect around Azalea roots or base. Is this true or would they get nutrients from them decaying?
In order for you to be able to leave your leaves in the soil with the plant would be to use mycorrhizae to break down organic material. This beneficial fungus will help unlock those nutrients to be available to the plant while keeping away fungus that would be harmful to your plant. Leaving dead foliage without this beneficial fungus will, more than likely cause harm to your plant.