Applying Dormant Oil
All About Dormant Oil
Why use a dormant oil spray? Some trees can be more prone to fighting the same pests or fungus issues year after year. Once trees leaf out, there isn’t much that can be done. But, consider this your reminder that you can try applying Dormant Oil in the early spring before buds and leaves are out.
What Plants Tolerate Dormant Oil
Any fruit-producing trees including apple, crabapple, nectarine, plum, pear, peach and cherry trees. Shrubs, such as currants, gooseberry and roses, euonymus, mugo pine, highbush cranberry and other ornamental plants that insects like to feed on.
Avoid application on Japanese maples, beech, redbuds, oak trees, dormant maples, dormant hickory, black walnut, smoke tree, azalea, Japanese holly, junipers, some cedars, blue spruce, dormant spruce, dormant Douglas fir or broadleaf evergreens as it may cause damage.
What is a Dormant Oil Spray Kit
Dormant spray kits are pretty straightforward. Dormant Oil Spray Kits contain two different ingredients in the box; horticulture oil (insecticide) and lime sulfur (fungicide) that are typically mixed in a 2:1 ratio (but always read instructions on the label for your kit!) and then sprayed onto your trees.
The oil will smother and reduce the instance of overwintering pests such as aphids, spider mites, scale insects, greenhouse whiteflies, mealybugs, plant bugs, lace bugs and some caterpillars. The fungicide will help reduce chances of rust, powdery mildew and black spot.
How to Use Dormant Oil
The most important part of application is to get the timing right. Apply after the snow melts, but before new growth starts – buds or blooms – because this oil can be harsh on your trees. Early spring is the perfect opportunity to apply it.
Ensure that when you’re ready to spray, you don’t mix up more than what you’re going to use, as it will loose efficacy if it sits. Mix according to the instructions on the box, and get a thorough application to the canopy or problem areas using a large sprayer or as directed. This product will only protect the parts that it coats.
Try to spray on a still day with no wind, and keep off-spray from reaching any trees that cannot tolerate dormant oil, and protect groundcovers planted under your trees with a drop cloth.
Let’s Grow Together
Dormant Oil Time Baby!
When spring is springing, it's time to do some preventative maintenance on fruit trees and other trees and shrubs.
Best Practices for Using Dormant Oil Spray Kits
- Always read and follow the instructions on the label.
- Never apply once leaves have broken bud! Don’t wait, we have time now before those buds leaf out.
- Apply when temps are above 5°C.
- Avoid application 48hrs before or after a freeze.
- Spray in the morning to give a full day to work and dry off.
- Ensure total coverage with a thorough coat on all problem areas.
- Only mix up what you need, applying fresh mix is best.
- Not a solution for ALL trees and plants (seriously, read the label).
If the time is right and you haven’t already got yourself a Dormant Oil Spray Kit, we have them available at Heeman’s.
Other Things You Can Do
Knock down and integrated pest management strategies can help you keep your trees and shrubs healthy and beautiful. Other things you can do help problem prone plants are:
- Rake up and remove leaves and fruit from affected trees throughout the season
- Use proper pruning strategies to encourage an open habit and great air circulation
- Research the plants you have and see what they like in terms of fertilizing, mulching and watering…and then do those things!
- Research to see what likes to eat the pests you have, and do your best to attract as many beneficial insects, birds and bats as possible.
With a little bit of research and the right timing, you can get your trees and shrubs looking their best this year! Have questions? We would love to see you in the greenhouse! Stop by to say hello with one of our Daymakers, or you can send us a message on social media.
