Ornamental & Tree Diseases

I had a fungus leaf spot problems on some of my trees and shrubs last season. When should I begin my fungicide application program this year for these diseases?

Because fungicides control plant diseases by protecting the plant against infection, like a coat of paint, spraying prior to infection will allow you to get the most for your fungicide dollar. So, the earlier you begin your fungicide application program, the more successful you will be in controlling plant disease. Once fungus leaf spots and blights become widespread in an ornamental planting, or on trees, fungicide application is of limited (if any) value in controlling disease.