Homemade dormant oil spray

Updated November 21, 2016

There are several different recipes available for homemade dormant oil. These concoctions are effective at smothering many common garden pests, such as spider mites and aphids, as well as killing fungi that lie in wait for warmer weather to attack fruit trees and other valuable plants. Dormant oils are applied roughly between November and March, or when the plants in question are dormant.

Combine 4.5 litres (1 gallon) of water, 2 tbsp of ultra-fine canola or horticultural oil and 1 tbsp of baking soda. This mixture was developed by researchers at Cornell University. Shake the mixture well to combine all ingredients.

Pour the mixture into a sprayer or hand-held spray bottles for small-scale jobs, individual plants or precise applications.

Spray the oil on your plants on a sunny, windless day. Try to achieve the most complete coverage you can.

Things You'll Need

  • Ultra-fine canola or horticultural oil
  • Baking soda
  • Sprayer or spray bottles
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About the Author

Based in Fort Collins, Colo., Dannah Swift has been writing since 2009. She writes about green living, careers and the home garden. Her writing has appeared on various websites. She holds a Master of Arts in English literature from the University of New Hampshire and is currently pursuing a certificate in paralegal studies.