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How to Manage Pests

Pesticide Information

Active ingredient: Horticultural oil

Pesticide type: fungicide, insecticide (oil), miticide

Synonyms: fungicidal oil; horticultural oils; insecticidal oil; mineral oil; narrow range oil; oil; petroleum oil; summer oil; supreme oil

See example products below.

Potential Hazard1 to
Water quality2
(aquatic wildlife)
Natural enemies
Honey bees3 People and Other Mammals
Acute4 Long Term5
Not listed

Acute Toxicity to People and Other Mammals4

  • Toxicity rating: Not Acutely Toxic

Long-Term Toxicity to People and Other Mammals5

  • On US EPA list: Not listed;
  • On CA Proposition 65 list: Not listed

Water Quality Rating2

  • Overall runoff risk rating: No Known Risk
  • Source: Pesticide Choice: Best Management Practice for Protecting Surface Water Quality in Agriculture. UC ANR Publication 8161.

Impact on Natural Enemies

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

Impact on Honey Bees3

  • Toxicity category: III - Apply only during late evening, night, or early morning

Pests for which it is mentioned in Pest Notes

AphidsApple and Pear ScabAsian Citrus PsyllidAvocado Lace BugBiological Control and Natural EnemiesBlack ScaleBrown Marmorated Stink BugCalifornia OakwormCodling MothCottony Cushion ScalesElm Leaf BeetleEucalyptus Redgum Lerp PsyllidGlassy-winged SharpshooterHackberry Woolly AphidLace BugsMealybugsOak Pit ScalesPowdery Mildew on Fruits and BerriesPowdery Mildew on OrnamentalsPowdery Mildew on VegetablesPsyllidsRedhumped caterpillarRoses in the Garden and Landscape: Diseases and Abiotic Disorderspowdery mildewRoses in the Garden and Landscape: Insect and Mite Pests and Beneficialsspider mites, scalesRoses in the Garden and Landscape: Insect and Mite Pests and Beneficialsscale insectsScalesSixspotted Spider MiteSooty MoldSpider MitesSquash BugsSycamore ScaleThripsWhiteflies

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. Dormant treatments are ideal because, with leaves removed from trees, coverage is much more effective. A pressurized sprayer is required for application. Repeat applications will be required for pests migrating in or appearing after application.

Precautions and Safety Equipment

Minimize your exposure to pesticides.  Avoid contact with eyes.  Wear eye protection, long pants, a long-sleeved shirt, and a hat that can be washed after each use.  Always read label of individual product for additional directions.

Always check the label before purchasing or applying a pesticide product for a specific pest on a specific plant to be sure it can be applied. Follow label directions precisely.


Example home, garden or landscape use products6

All Seasons Horyticultural & Dormant Spray Oil Ready to Spray • Bonide All Seasons Horticultural & Dormant Spray Oil • Bonide All Seasons Horticultural Spray Oil Ready to Use • Master Nursery Pest Fighter Year-Round Spray Oil • Monterey Horticultural Oil • Ortho Volck Oil Spray • Pest Fighter Year-round Spray Oil • Year-Round Spray Oil


  1. Potential Hazard Rating: VL=Very low, L=Low, LM=Low to Moderate, M=Moderate, LH=Low to High, MH=Moderate to High, H=High, VH=Very High, N=None, NKR=No Known Risk, —=No data
  2. Water quality ratings from Pesticide Choice: Best Management Practice (BMP) for Protecting Surface Water Quality in Agriculture, ANR Publication 8161, or the USDA-NRCS WIN-PST database—see Pesticides: Water-Related Toxicology of Active Ingredients.
  3. Honey bee ratings are: (Very High) I-Do not apply to blooming plants; (High) II-Apply only during late evening; (Moderate) III-Apply only during late evening, night, or early morning; and (Low) IV-Apply at any time with reasonable safety to bees. For more information, see How to Reduce Bee Poisoning From Pesticides (PDF), Pacific Northwest Extension Publication PNW591.
  4. Acute oral toxicity ratings for people and other mammals based on LD50 and US EPA Acute Toxicity Ratings system: H = Highly Toxic (LD50 <50), M = Moderately Toxic (LD50: 50-500), L = Slightly Toxic (LD50: 500-5000), VL = Not Acutely Toxic (LD50 >5000)
  5. Long term ratings indicate whether the active ingredient is on the California Prop 65 list, which indicates if materials are known to cause cancer or reproductive toxicity, or whether the US EPA has classified the pesticide as "likely to be carcinogenic to humans", "Group B-Probably Human Carcinogen", or "Group C-Possible Human Carcinogen."
  6. These products were registered for home and garden use in California in July 2013. Professional use products are not included. If no example products are listed, this active ingredient may be available only for professional use. Individual products are registered for specific uses on specific sites. Read the label to determine if the product is registered for your use. Note that some products may be formulated with additional pesticides.

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