Dormant sprays can be used on ornamental, fruit and nut trees to treat a variety of problems and prevent others. While they cannot treat all problems faced by peach trees, they are an integral part of peach tree management. Dormant sprays are the first step of the season used to manage insect and disease problems before they have the opportunity to get out of hand.
What is Dormant Spray?
Dormant spray is a common term for a variety of products applied to deciduous trees during their dormant or leafless phase in the winter months. It is used to prevent both insect infestations and disease infections caused by overwintering organisms. Dormant sprays cause minimal damage to helpful insects.
Types of Dormant Sprays
There are four basic dormant sprays or treatments that can be applied to peach trees. Latex paint is applied to the trunks of young trees. Copper is used for trees with or prone to canker. Lime-sulfur applications are made to control fungal and bacterial infections. Oil is applied to treat an existing or prevent a potential insect infestation.
How Dormant Sprays Work
In the case of latex paint, the coating is applied to the trunk when trees are young to protect against winter sun scald that can cause splitting. The crevices created by splitting can harbor overwintering pests. All other dormant treatments are sprayed on the tree after leaves have fallen. Dormant sprays coat the bark and seep into cracks and crevices where pests live. Oil essentially smothers eggs and larvae. Copper and lime-sulfur applications prevent infections from being able to take hold in wounds in the peach tree.
When to Apply
In all cases, all leaves should be off the tree. For oils, apply on days when temperatures are expected to rise. If applied when temperatures are below 35 F, the peach tree can be damaged. Latex paint should be applied as soon as the tree has lost all its leaves for the best protection. All other dormant oils can be applied anytime during the dormant period as long as no green tissue appears just prior to bud break.
Dormant sprays can be applied at the grower’s convenience when weather conditions are mild. With leaves out of the way, the application can get directly to the bark and wood of the tree where it is needed. By applying dormant sprays before problems emerge, many problems are avoided altogether. Dormant oils perform their job long before bud break when helpful insects such as pollinating bees could be harmed by other insecticides.