What is Dormant Oil?
Dormant Oil is usually a petroleum-based product that is used to control mites, insects and some plant diseases. They act by smothering the insect, egg or cocoon. This process is not selective so if you have populations of beneficial insects, bees or cocoons of butterflies overwintering in the bark furrows or branches it will kill them too. Application of Dormant oil must be thorough and you must have the insects you are trying to control present. Once the oil has dried it is not longer active so any new insects or pollinators will not be affected and it is relatively non-toxic to other animals and once dry it breaks down quickly.
When Should I Use It?
You should only use Dormant Oil, as with any other pesticide, when you have an active insect problem that you need to knock down. Dormant oil should be used as the name suggests, during the dormant season (winter), on deciduous trees such as apples or plums. Ensure your plants are fully dormant and not beginning to break bud or leaf out. The trees you will be spraying the dormant oil on must have an active problem such as coddling moth or winter moth or other insect, mite or disease that the oil will control as there is no preventative or residual action. Your trees should be dormant, follow all safety directions and thoroughly coat the affected tree.
What Else Should I do to keep my Trees Healthy?
During the growing season, continue to monitor the insects and treat with cultural practices such as pruning for an open habit, removing affected parts, removing fallen fruit, encouraging a wide range of insects, birds and other predators into the garden to further control the pest.
Make sure your trees and shrubs are healthy! Tree circles, composted mulches or green mulches and feed as needed. Healthy plants have better resistance and are less attractive to pests and disease.
