|Should I spray my azaleas and rhododendrons with dormant oil or an anti-desiccant|
|I think you need these two items defined. The "winter protector" is really an "anti-desiccant" which keeps your rhododendrons and azaleas from drying out. It helps seal the plant so it doesn't lose valuable water resources. It is sprayed on your rhodies in the late fall to protect them from drying and freezing wind in the winter when the plant is less able to take up the water it needs.
Dormant oil on the other hand is sprayed on deciduous trees in the early spring when they are in a dormant state. These oils are used to kill overwintering insects which can be found on the leaves and bark of these trees, and are most vulnerable in the very early spring.