Estimated read time: 2-3 minutes
This archived news story is available only for your personal, non-commercial use. Information in the story may be outdated or superseded by additional information. Reading or replaying the story in its archived form does not constitute a republication of the story.
Take heart in the orchard because there is one spray that you can cross off your list. Thank our dry Utah Climate for this. Last hour we talked about the delayed dormant spray. It is one of the most useful and important sprays for our area to control a great number and variety of home garden pests. Unfortunately many gardeners get this spray confused with another common but unnecessary and unneeded spray that is often sold in our area. Don't misunderstand what a dormant spray for Utah Gardeners consists of. Dormant sprays for our area are horticultural spray oils (Volck, Superior, Supreme or other brands) that you mix with an insecticide. Insecticides increase the effectiveness on early-season pests, but organic gardeners can use the oils without the insecticides. Premixed products labeled dormant spray are dormant disease control. Dormant Disease control is the one that you can cross off your list! Dormant disease control is a lime-sulfur spray. Lime sulfur is formulated to control diseases, not insects. It is not needed in our area, as we don't usually get peach leaf curl, apple scab and other diseases it controls. They are calcium sulfides, lime sulfur or similar type products. If you have ever used the products you will remember it. Open the bottle for an unforgettable experience. They have a strong, rotten egg odor but do very little to help fight pests because the trees usually do not have the diseases they control. These lime sulfur sprays are very important in humid climates but Utah is not one of them. they are applied in the fall in other climates to control potential diseases. Always avoid spring applications of these products. The combination with the dormant oil can have serious repercussions. Never add sulfur, including lime sulfur on the same plants or near the same time as you are using oil sprays. The combination of oils and lime sulfur can burn plants very badly. This often disfigures the leaves and stems and can permanently affect the growth. Lime sulfur or dormant disease control is labeled for powdery mildew control but there are much more effective and must less damaging products to use for this disease. Larry A. Sagers Regional Horticulturist Utah State University Extension Thanksgiving Point Office