Mineral Oil

Monterey Horticultural Oil contains mineral oil and functions as an insecticide, fungicide and miticide. It is listed as organic by the Organic Materials Review Institute (OMRI). However, use of this product is only recommended during vegetative growth.



Target Pests: Aphids, Eriophyid Mites, Leafhoppers, Spider Mites, Whiteflies, Fungus Gnats

Target Pathogens: Powdery Mildew, Gray Mold, Sooty Mold, Black Spot, Rust

Mode of Action: As an insecticide and miticide, horticultural oil is used to cover the egg, larval and nymph stages causing suffocation. Contact with the pest must be made for the oil to be effective. As a fungicide, this product interferes with the fungal pathogens ability to attach to the host.

Application Tips: Oils kill primarily by smothering insects and mites and an oil spray will kill only insects it comes in direct contact with at the time of application. Thoroughly spray so that all insects are covered. Be aware that many insects prefer the undersides of leaves or may be under sepals or leaf buds where they are hard to reach. A pressurized sprayer is required for application. Repeat applications will be required for pests migrating in or appearing after application.

Impact on Beneficial Insects:

  • Overall toxicity rating: Low
  • Specific impacts: predatory mites (Low), parasitoids (Low), general predators (Low)


University of California Statewide Integrated Pest Management Program

Using Horticultural Oil Sprays for Pest Control by Donald Lewis, Department of Entomology Iowa State University