This is a generic term for any spray applied to deciduous trees during fall, winter, and early spring while the branches are still bare, before they experience any spring growth.  There are many different products that can be used,–it’s more the timing which makes it a dormant spray.  It is used to prevent insects and diseases that can emerge in the Spring, and can be one of the most beneficial things you do for your trees and shrubs.

WHAT DO DORMANT SPRAYS TREAT? Dormant sprays are used primarily on fruit trees, although they can also be used to address problems on shrubs and roses as well. They help destroy insect eggs, over-wintering adults and hatching larvae. They can also kill fungal infestations that could spread in warmer weather and become much harder to control. Besides being one the most effective options, spraying during the dormant season is the least disruptive to beneficial insects and the environment. For those that prefer organic gardening, many of our dormant sprays are also organic. How great is that?

WHAT ARE THE DIFFERENT KINDS OF DORMANT SPRAY?  There are three primary kinds of Dormant Spray; Oils, Lime Sulfur and Copper-based sprays. The oils are used to treat insect pests such as scale and aphids. Lime Sulfur is very effective against fungal diseases such as leaf spot and powdery mildew. Copper-based sprays are also very effective fungal-fighters and are a little more effective against bacterial problems than Lime Sulfur. In cases with known problem plants, two sprays like oil and lime sulfur for example, are often combined to give broad spectrum control of several problems.

Dormant sprays are especially effective against scale insects, mites, aphids, and leaf curl and shot hole. Some issues, such as Peach leaf curl requires persistence in order to be effectively controlled. For these, you would treat several times during the dormant season, instead of just once. Apple Scab and Apple Maggot are also common issues in our area. However, both of these issues are actually treated later in the Spring, when buds are just beginning to swell.

WHEN DO YOU USE DORMANT SPRAY? In general, either a dormant spray application, a delayed-dormant spray application or a combination of the two are called for. Dormant spray must be used before the trees experience any spring growth. For us, this is usually between November and March. Delayed-dormant sprays are designed for use just after the buds begin to swell, but before the trees start to leaf out or flower. This usually occurs in late March to early April.

Dormant oils should not be used when the tree is in flower, since they can be deadly to pollinators. Oils- The best time to spray for insects is early to mid-march, just before the trees begin to break out of dormancy. Lime Sulfur- Spraying occurs throughout dormancy depending on what is being treated. Copper- Spraying occurs throughout dormancy depending on what is being treated.

The use of dormant spray is a  great example of how knowing specifically what you are trying to control, can make your treatments much more effective, saving you both time and moneyWant to give it a try? Depending on your tree (or shrub) and what you are needing to control, specific spraying schedules will be called for. Our expert staff can help you choose the right product as well as explain what schedule you should be using.