Kristen's Natural Pest Repellant Oil

Updated July 28, 2007

This is my own recipe to help repel pests in my garden, but you can spray it anywhere outdoors, even on buildings as long as the surface won't be harmed by oil or stained. Some ingredients also kill insects on contact, but effectiveness varies.

• Alcohol (the kind you drink) The higher the proof (alcohol content) the better. Since you won't be drinking it, don't worry about flavor.
• Hot Chilies The stronger the chili pepper, the more capsaicin it has, and the more effective it will be. Habanero chili peppers have the most capsaicin of commonly available chilies, followed in order by scotch bonnet, Jamaican hot, Thai, and cayenne (cayenne is the least hot of this list and is the minimum capsaicin level you should use for this recipe). Mammals (like rodents) don't like capsaicin. Capsaicin also repels some insects. (You can even use it to make your own pepper spray to protect yourself against violent criminals, ferocious dogs, and even bears, but that's another recipe.)
• Optional Ingredients These items are also repel various pests. I try to include as many of them as possible in my spray.
  • Garlic Cloves
  • Basil Leaves
  • Spearmint Leaves
  • Peppermint Leaves
  • Eucalyptus Leaves
  • Chrysanthemum Flowers
  • Marigold Flowers
  • Pennyroyal Leaves
• Canola Oil Canola oil repels many types of insects and can be sprayed on leaves, nuts, and fruits of most plants (I have yet to find a plant it can't be sprayed on).

1. Put on some rubber gloves, a thick long sleeve shirt (or two), pants (not shorts), and goggles (yes I'm serious), to keep the chilies from causing skin or eye irritation (just trust me, you'll be thankful).
2. Put your chilies and other optional ingredients in a blender and add just enough alcohol to cover them. Turn on your blender and let it puree. Keep the lid on the blender; you don't want any fumes to escape (especially if you are sensitive to capsaicin).
3. Let the mixture sit for at least an hour to allow the alcohol to extract the oils from the flesh of the chilies and optional ingredients.
4. Strain the mixture by pouring it through a double layer of cheese cloth or a coffee filter, and discard the solids.
5. Pour the strained, liquid mixture into a large shallow pan (like a roasting pan) and put it outside.
6. Let the mixture sit outside until all of the alcohol has evaporated, leaving behind just the oil.
7. The oil mixture you now have is very concentrated (especially if you used a very hot chili). To dilute it, mix it with canola oil. I dilute mine by 50%.
8. Put the mixture in a spray bottle and label it. Make sure that you list the specific ingredients on the bottle.
9. Test the spay on a small section of the surface you want to spray first. Spray it on a few leaves of the plants you wish to spray and wait 24 hours. If the leaves turn brown, you need to dilute the mixture more. Spray it on a small section of building surfaces and wait 24 hours to see if it stains or causes any damage.
10. Once you figure out the necessary dilution that you need for your particular plants and surfaces, spray everywhere you think pests will be attracted to and especially anything a mammal might eat (such as fruit). You will need to reapply the spray every two weeks and after every rainfall. Make sure you water your plants at the base, don't spray their leaves, to avoid having to reapply the spray after every watering.

Sources: http://www.epa.gov/pesticides/biopesticides/ingredients/factsheets/factsheet_011332.htm,