Q. how often can I spray my evergreen shrubs with Wilt-Pruf, in the winter?
Winter protection for your plants:
Wiltproof, an anti-desiccant will help retain the moisture in the leaf/needle for up to 4 months in the winter. Wilt-Pruf is a natural product derived from the resin of the pine tree. Since it makes no pesticide claims, it does not require registration with the EPA. It is an anti-desiccant which means it acts as a protective coating of the leaf or needle of the plant, substantially reducing water loss during high periods of stress. More from Missouri Botanical Garden link:
Hope this helps