“Dormant spraying with horticultural oils kills over-wintering insect eggs, mites, soft-bodied insects, and some scales by blocking the supply of oxygen and suffocation the pests. Applied in winter, the dormant spray does not reach fruits or harm beneficial insects. Dormant spraying is done in 2 or 3 doses, and the first application is made in December. Deciduous fruit trees, some deciduous shrubs and rose bushes should be sprayed after they have lost their leaves.

• Horticultural oils (also called dormant oils) are highly refined petroleum oils that are manufactured specifically for use on plants.
• Mineral Solutions of lime and copper sulfate are also used as dormant oils sprays to control specific pests on specific trees. They can be combined with horticultural oil for broader coverage.
• Lime Sulfur controls anthracnose, apple scab, brown rot, peach leaf curl and powdery mildew.

This time of year it’s most important to do your first spray of Peaches, Nectarines and Apricots for Peach Leaf Curl; a water-activated fungus which attacks during the blossoming stage. It is important to spray just before the pink buds open when they resemble popcorn about to pop. Bordeaux mixture (hydrated lime and copper sulfate) controls brown rot, peach leaf curl, some grape diseases, some apple diseases, downy mildew and many fungal diseases. Sulfur controls fugal spores, brown rot, peach scab, apple scab and powdery mildew.

Be sure to follow the application directions. Many lime and sulfur based oils are caustic so wear protective clothing, goggles and long rubber gloves. Use a clean, quality sprayer. Aim a fine spray onto the bare branches and limbs and cover. Spray only when the temperature is above 45 degrees F. Hose everything off when done and wash your clothes.”