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Homemade Insecticide for Plants

By Marie Price
Woman gardening

After spending many hours diligently weeding, watering and fertilizing your garden, it is very frustrating to encounter invasive insects on your plants. Aphids, mites, flies and caterpillars can cause irreparable damage to your garden if they are not controlled. Store-bought insecticides, however, can be expensive and may pose a threat to your pets and children. There are many ways to make effective and safe insecticides easily at home.

Using Soap and Oil

Dish soap and sponges

Insecticidal soaps are particularly effective for soft-bodied pests such as aphids, whiteflies and spider mites. The soaps are absorbed through the insect’s body and clog their membranes, therefore killing them. These soaps are highly effective for pest control and are safe for humans, animals and beneficial bees. To make your own insecticidal soap, use only soft soaps, not harsh detergents, which can damage your plants. Take three teaspoons of Murphy’s oil soap, Ivory dish washing liquid or castille soap and dissolve it in 3 cups of warm water. Add 1 cup of vegetable oil or mineral oil and mix. Pour the soap mixture into a plastic spray bottle for easy application. It is best to apply a soap insecticide no more than once a week and preferably after a rainstorm. If you have particularly tender or young plants, dilute the solution with more water to prevent unintentional damage.

Other Homemade Insecticides

Garlic cloves

Insects are easily repelled by strong odors and tastes. Using natural ingredients, such as garlic, cilantro and hot chili peppers, can be very effective against controlling insects as well as repelling snails, slugs and small mammals. For a garlic spray, add five to six crushed garlic cloves to your homemade insecticidal soap. Let the garlic steep in the mixture overnight then strain the insecticide through cheesecloth and into a spray bottle. Garlic spray works well against aphids and caterpillars and can help prevent fungal and mildew problems as well. A cilantro spray is best for spider mites and aphids and can be easily made by boiling one bunch of cilantro, leaves and stems, with 4 cups of water for 10 minutes. Strain the mixture through cheesecloth and let the spray cool overnight. Pour the cilantro spray into a spray bottle and apply where needed. Chili peppers will deter a wide variety of pests including birds, rabbits and mice as well as insects. Place 10 Habanero or Serrano chilis in 4 cups of hot water for 10 minutes. Allow the chilis to steep overnight in the water then add 3 teaspoons of soft soap to the chili mixture. Strain the mixture through cheesecloth and apply to your plants. Be careful, however, because the chili mixture can burn tender plants and should be used sparingly.

 

About the Author

 

Marie Price is a freelance food, arts and gardening writer. She is a graduate of Pratt Institute of Fine Arts in Brooklyn, NY where she studied painting and art history. She also has many years experience with catering and baking. She currently works as a marketing director and technical writer at a nursery, where she also uses her knowledge of plants.