Protect Your Trees & Shrubs with Dormant Oil This Fall

By October 21, 2017Plant Care

As the leaves change and fall to the ground, you need to call your lawn care professional to apply dormant oil to their bark.


Because you want to protect one of your biggest investments—your ornamental trees and shrubs—from insects that hibernate and lay eggs in your trees and shrubs.

In this blog post, you’ll learn what dormant oil is, how it protects your landscaped trees and shrubs, as well as why you need a professional lawn service to apply it.

What is Dormant Oil?

Dormant oil, also known as horticultural oil, is used to prevent soft-bodied insects, such as aphids, mealy worms, thrips, whiteflies, mites and scales, from infesting your ornamental trees and shrubs over the winter.

Vegetable oil or petroleum is used as the base in horticultural oil. To use it as a spray, your lawn care professional adds water to the oil before applying it to your woody ornamentals.

During the fall application, dormant oil is applied directly to the bark of trees and shrubs to protect them from menacing insects.

Horticultural oil is considered a preventative and less toxic than regular pesticides. Plus, it’s proven to work.

Now’s the time to add pre-emergent weed control to your GA lawn.

Here are four other benefits to using horticultural oil:

  1. It’s non-toxic to people and pets
  2. It doesn’t affect beneficial insects that prey upon destructive pests
  3. Typical tree-infesting pests won’t develop a tolerance toward it
  4. It’s relatively inexpensive.

Dormant oil is applied in the fall because most of the days are below 90°F and lower humidity allows the oil to penetrate into the trunk, stems and branches.

How Does Horticultural Oil Work?

Once it’s applied to your trees and shrubs, horticultural oil will smother any insects that live in the bark. Plus, it keeps insects from invading during the winter months.

If rain is forecasted on the day of your application, your lawn technician will reschedule your appointment for another time. Horticultural oil needs 24 hours to absorb into your trees’ bark and rain will wash away the application.

Fall is the perfect time to add a preventative to stop spring lawn patch from developing over the winter.

Why Your Landscape Plants Need Horticultural Oil and Plant Health Care

You paid a lot of money for your trees, shrubs, groundcovers and other perennial plants. And the best way to preserve these investments is through plant health care.

Right now, your plants need dormant oil to protect them throughout the winter.

Later in the winter, your trees and shrubs will get a second application of horticultural oil to prevent insects from attacking your woody plants as well as prevent insect eggs from hatching during the spring.

Your plant health care technician will apply horticultural oil on tree and shrub leaves as they flush out in the spring.

In addition to the spring horticultural oil application, you should consider signing up for a full season of plant applications to keep your investment healthy and beautiful.

Here’s what you get

  • Late Winter Prevention using horticultural oil, to smother any insects living in the bark of your woody plants as well as preventing insect eggs from hatching. Horticultural oil is added to leaves too.


  • Early Spring Fertilization: Give your landscaped plants a shot of nutrients to promote growth, deepen color, prevent diseases and give your plants the ability to survive dry, hot weather.


  • Pest and Weed Control: There are three different control applications from the spring, through the summer and into the fall. These controls prevent insects and diseases from infecting your landscaped plants.


  • Another Round of Prevention: Toward the end of the growing season, it’s time to apply dormant oil to your trees and shrubs to protect them from soft-bodied insects during the winter.

It takes a lot of work to keep your landscaped plants beautiful and healthy. But you don’t want to waste your precious time to make sure that your ornamental trees and shrubs get the right amount of dormant oil, pest and weed control or the proper amount of fertilization.

Instead, you need a professional lawn care company to apply horticultural oil, nutrients, weed and pest control to your property’s woody ornamentals.

If you want to protect one of your major investments—your landscape—then you need to call us at Agropro, 678-445-9990 or fill out our contact page.


Russ, Karen, “Less Toxic Insecticides,” Clemson University Cooperative Extension: HGIC 2770., “Horticultural Oil.”

Agropro Lawn Care Service~ Agropro provides Lawn Care and Plant Health Care services to these areas in North Georgia: Alpharetta, Atlanta, Buckhead, Canton, Cumming, Dunwoody, Johns Creek, Marietta, Milton, Roswell, Sandy Springs, and Woodstock.