About Dormant Oil Treatment

technician spraying pest control

One perk of the winter season is the lack of pests. Surviving the cold months becomes more tolerable knowing all the little critters won’t be pestering you. Once the weather begins to warm up you should start thinking about hiring a professional to spray your yard with a dormant oil treatment to help prevent against pests invading your personal space.

What is Dormant Oil Treatment?

pest exterminator

Dormant oil treatment refers to the time of season “dormancy”, not the actual oil itself. Through the winter season, both plants and insects become dormant. Insects will lay their eggs in the soil and on your trees before the harsh winter months appear. The adult insects then die during the winter while their eggs wait it out to hatch in the spring season. However, some adult insects will wait out the winter as well. The oil is usually made from refined petroleum oil or cottonseed oil. When the oil is sprayed it works its magic by suffocating the pests. The oil may either block the pests breathing pores, penetrate through and destroy their cells or just dry them out. Either way, once the dormant oil is sprayed it will take care of any lingering pests and eggs that are waiting to become active again during the warm Spring season. The oil does not leave a harmful residue and has low toxicity to humans, animals, and beneficial insects. The reason beneficial insects are not harmed is that they are not present during the appropriate times of spraying. However, once dried the oil no longer works to control pests so thorough coverage is essential. Depending on the severity of population, you may need a second treatment to fully take care of your pest problem. Eggs are often stacked on top of each other and it may be difficult for the first round of oil treatment to penetrate far enough down to the bottom layers.

Why and When to Use Dormant Oils?

The treatment of dormant oils targets killing overwintering pests, including mites and scales. These pests when they become active in the Spring can cause plant injury and even end up killing your trees and plants. To treat your plants and attempt to rid of the pests in later months is more difficult. Multiple different treatments at varying sources will be needed once the insects are in their active stages. It’s better to treat the problem at its source during the early stages with just one or two preventative dormant oil treatments. Insecticide treatments may not be needed when using dormant oil. Not using insecticides will preserve natural enemies of these pests, including predators that provide free control of these unwanted pests.

pest control being sprayed in yard

The best time to have a dormant oil treatment applied is completely weather dependent. You need to have the application before the buds on trees have begun to swell. However, the temperature needs to stay above freezing, at least 40 degrees F, for a minimum of 24 hours. Wind and rain can also have an effect on the application, so a calm day is a must. With these specifications, it’s best to have the treatment done around March or April. For the dormant oil treatment to be as effective as possible it should be done in conjunction with good yard sanitation. Rake up and get rid of fallen leaves, debris, and grass that could potentially be harboring the overwintering insects. Also, do any necessary pruning to your trees and shrubs. This allows for maximum coverage of the oil spray because there are no extra leaves in the way.

Hire a Professional

The use of dormant oil treatment is not harmful to humans, animals or beneficial insects. However, if not sprayed at the right time or sprayed appropriately it can cause damage to your trees and shrubs. If sprayed after bud break, the oil can cause the young leaves to die or turn the edges black. If not sprayed at the appropriate time, the dormant oil will not be effective. When you hire a professional these questions will be answered. They are trained and qualified to administer these treatments effectively and efficiently. Knowing you have a trusted technician taking care of your yard will help ease your stress and also save you time and money. Make sure to call in and get your dormant oil treatment scheduled before it is too late!

Spring Services You Need

pest control sign with dead pest


As the weather begins to warm up, so do the pests and potential diseases. No one likes to have their home and yard infested with pesky pests and diseases. The best thing you can do is to take preventative measures to stop these unwanted problems in their tracks. Star Pest Control offers many residential and commercial services such as pest control and weed and feed for your yard, but we also offer the following services as well:

pest control being sprayed in yard
  • Dormant Oil Treatments: This is to kill overwintering insects and eggs. Best applied before leaf budding starting mid-March.
  • Deep Root Injection Fertilization: This is for your trees and shrubs. Best to have done in March or April.
  • Organic Preventative Treatment: This is for codling moth in apple trees. Best to have done before May 15th.
  • Aphid Sprays: Optimal during mid-summer.
  • Crabgrass Pre-Emergent in Turf
  • Broadleaf Pre-Emergent in Turf
  • Shrub Bed Pre-Emergent: This treatment is great in landscape beds with no weed barrier or a failing barrier.
  • Preventative Treatment: Used for tree insect borers like pine bark beetle and aspen borer.
  • Plant Growth Regulators: This type of treatment makes it so you don’t have to trim and hedge as often.
  • Grub Prevention 
  • Bare Ground and Sterilant Treatments: This treatment is used on driveways, parking lots, and non-ornamental rock beds.

There are many different types of services you can utilize to fully take control of your property and its surrounding yard. Don’t wait until it is too late and you are overrun with infestations. Call ahead to Star Pest Control to schedule your services. We can help you plan for your yearly care and get ahead of these pesky pests and diseases.