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How to Make Rosemary Insecticide

By Jolene Armand ; Updated September 21, 2017
Rosemary deters insects from invading your garden.
rosemary background image by Xavier MARCHANT from Fotolia.com

Gardeners have been using herbal insecticides as a safe alternative to chemical based insecticides for thousands of years. Though many herbs, including rosemary, ginger and bay leaf, can kill and deter insects in your garden, they are generally safer for small children and pets than commercial, chemical-based insecticides. Preserving the herb in a plant-based oil both maintains the beneficial properties of the herb and creates a compound that can be sprayed, spread or mixed easily.

Step 1

Place 4 ounces of fresh rosemary at the bottom of the clear glass jar. Pour in enough safflower oil to cover the herbs. Close the jar with the cover and place in a warm, sunny spot for at least two days.

Step 2

Open the jar and pour oil through the strainer into the measuring cup. Discard the remaining herbs.

Step 3

Pour 2 ounces of the strained oil into the spray bottle. Add 2 ounces of liquid soap and 8 ounces of water.

Step 4

Shake bottle until mixture is blended. Shake the bottle before every use, because the components will separate.

Step 5

Spray evenly over the plants to be treated. Hold the bottle at least 12 inches away from the plants when you spray.


Things You Will Need

  • 4 oz fresh rosemary
  • Safflower oil
  • Clear glass jar with cover
  • 2 oz liquid soap
  • Water
  • Spray bottle
  • Strainer
  • Measuring cup

About the Author


Jolene Armand has been writing since 1999. She has worked as a marketing copywriter for medical, dental and legal services companies and as a freelance medical and legal researcher. Armand is currently pursuing a dual Bachelor of Science in biology and Bachelor of Arts in English.