Spray fruit trees with fungicide in early spring before flower buds open. Spraying fruit trees is a standard practice farmers and gardeners take to help control plant diseases and insect pests and also to provide needed nutrients. … General purpose sprays take care of both insects and fungal diseases.
The best time to spray fruit trees with a preventative dormant oil is in late winter or early spring. This effort helps to protect trees from overwintering pests, larvae and eggs, which improves success with controlling pests during the growing season.