When is a dormant spray applied to trees?

A dormant spray is applied to trees before the buds have opened or after the trees have gone into dormancy. This timing is crucial because dormant sprays are often used to manage pests and diseases that may affect trees during their growing season. Applying the spray during dormancy takes advantage of the reduced physiological activity in the trees, minimizing potential damage to the tree itself while effectively targeting overwintering pests or fungal spores.

This method is also beneficial because, during the dormant period, trees are less susceptible to injury from pesticide applications since they are not actively growing. As a result, applying before buds open allows for thorough coverage of the tree surfaces without risking harm to tender new growth.

In contrast, spraying during the spring growth period would not be ideal as the active growth could lead to injury to new buds and leaves. Applying after the first frost may not target the intended pests effectively, as many may have already emerged or become active. Likewise, late summer applications would generally not be classified as dormant sprays, as this is typically a period of vigorous growth for many trees.