While you’re happily enjoying fall, munching caramel apples, and cheering at football games, a lot of insects are busy laying eggs in your trees and shrubs.
They’ll lurk there all winter, then in spring, while you’re busy hiding Easter eggs, their eggs will hatch into hungry larvae that will devour your precious trees.
Terrifying, right? How to stop this dastardly devastation?
That’s where dormant oil spray comes in. Here’s everything you need to know to protect your trees before damage begins.
What is Dormant Oil for Trees?
We know what you’re thinking. If this oil is dormant, how powerful could it be?
It’s named for when you apply it — when trees and plants are dormant.
Also called horticultural oil, dormant oil spray is a highly refined petroleum product used as an insecticide to suffocate insects and insect eggs that have overwintered on trees and shrubs.
Instead of poisoning the bugs, you’re basically smothering them with the oil. The oil kills any lingering insects as well as their eggs, so they won’t hatch in the spring.
Yes, suffocating them seems pretty harsh, but would you rather have hungry bugs devouring your precious trees? No, you wouldn’t.
Applying dormant oil for trees at the right time can prevent significant damage.
Dormant oil is especially effective against:
- Aphids
- Scale insects
- Spider mites
- Other soft-bodied overwintering pests
When and How to Apply Dormant Oil
When Should Dormant Oil Be Applied?
Dormant oil is applied in late winter or very early spring, just before trees begin to bud.
Timing is critical:
- Too early and it may wear off before pests emerge
- Too late and you risk damaging tender new growth
Ideal application happens when temperatures are consistently above 40°F, but before bud break.
How Is Dormant Oil Applied?
Our technicians in Boise and Idaho Falls begin applications in early to mid-March. We:
- Spray all branches and twigs, ensuring thorough coverage
- Pay special attention to bark crevices where pests lay eggs
Proper dormant oil application creates a barrier that controls insect eggs before they hatch, preventing major damage later in the season.
Benefits of Dormant Oil Treatment
Using dormant oil for trees offers several advantages:
- Prevents early pest infestations
- Reduces the need for stronger insecticides later
- Minimizes tree stress from feeding damage
- Supports healthier growth in spring and summer
If you struggled with aphids, scale, or spider mites last season, dormant oil spray is your best early defense.
Is Dormant Oil Safe for Trees?
Yes — when applied correctly. Dormant oil is filtered and refined to minimize risk to plant tissue. However:
- Never apply on budding or blooming trees
- Follow proper dilution rates and weather guidelines
Our licensed Lawn Buddies technicians ensure application is safe, accurate, and effective.
FAQs About Dormant Oil
What is dormant oil used for?
It’s used to smother overwintering insects and eggs before they hatch.
Does dormant oil hurt trees?
Not when applied at the right time. It's safe for most trees when applied before bud break.
What pests does dormant oil treat?
It’s effective against aphids, scale, mites, and other soft-bodied pests.
Can I apply dormant oil myself?
You can — but proper timing and technique are key. Many homeowners prefer to leave it to pros.
Dormant Oil Spray Services in Idaho
If your trees had pest issues last year, now is the time to act.
Lawn Buddies offers dormant oil applications for customers in Idaho Falls and Boise as part of our Complete Lawn Care Program. It’s one more way we keep your lawn and landscape healthy — with no extra hassle.
We bundle fertilization, weed control, grub control, and plant health care treatments like dormant oil into one easy six-visit plan.
Ready to Protect Your Trees From Hungry Pests?
Don't wait until damage appears — get ahead of pests with Lawn Buddies' targeted dormant oil treatment.
Get started today: Fill out the form on this page, call us at (208) 656-9131, or explore our Plant Health Care Services online.
Because a healthy lawn starts with healthy trees — and bugs don’t take the season off.
Image Source: Spider Mites
