Dormant Oil for Apple Trees

Dormant oil helps alleviate pests living on apple trees.

Gardeners use dormant oil to help get rid of pests that spend the winter on apple trees. However, the oil does not prevent diseases or stop insects that attack the fruit of the tree later in the growing season.

Description

Dormant oil is made from highly refined petroleum oil. The spray is diluted with water. The oily spray helps to smother scale and other adult insects and their eggs.

Application

The best time to apply dormant oil is in early spring, when temperatures stay above freezing. Choose a day for spraying that will be followed by 24 hours of non-freezing weather. Apply the oil about one week before new leaf buds open.

Pests

Some of the insects that dormant spray helps to kill include scale, red spider mites and aphids. Aphids suck on the sap from the leaves, leaving an unattractive honeydew substance. Red spider mites create small speckles as they chew on the leaves. Scales are tiny insects that eat the immature apples, causing a general decline when widespread infestation occurs.

References

• University of Illinois Extension Stateline Yard & Garden: Spring Care of Apple Trees
• Texas A&M AgriLife Extension: Fruit Trees
• Ohio State University Extension Fact Sheet: Spider Mites and Their Control

Resources

• North Carolina Cooperative Extension Service: Growing Apple Trees In The Home Garden