When to Apply Dormant Spray to Northwest Apple Trees?
- Toward the end of winter, from late February into March, gardeners in the Northwest should apply dormant oil spray to their apple trees. Make sure to apply the spray before new leaf buds on the tree pop open. Ideally, apply the oil about one week before the buds are ready to open up.
- The spray works best on days when temperatures stay above freezing. For the most effect, plan to spray on a day that's followed by 24 hours of weather that does not drop below freezing temperatures.
- Apple trees only require dormant spray in the event of an insect infestation. The spray helps kill scale, spider mites and aphids. Some pests, such as aphids, can be controlled through natural predators, making dormant spraying unnecessary.