Spider mites are one of the most common insect pests found in vegetable beds and backyard gardens. While chemical pesticides like carbaryl can correct this problem, you can also try an all-natural treatment made of soaps or plants. Capsaicin, the active chemical in cayenne pepper that makes the pepper spicy and hot, is one such alternative. Cayenne works well against insects that feed on plant tissue, such as spider mites, helping to kill any existing mites while deterring future mites from visiting the area.
Garlic and Cayenne
Cayenne's capsaicin kills mites by damaging their nervous system, while garlic oil is lethal to spider mites. Combine the two for a potent weapon against spider mites on your plants. Blend one garlic bulb with a small onion -- the onion acts as an additional insect deterrent. Pour the pulp into a quart of water and stir in 1 teaspoon of powdered cayenne pepper. Allow the concoction to set for 60 minutes, and then strain out the solid matter with a cheesecloth or sieve. Pour the resulting liquid into a spray bottle and spray the solution on the afflicted plants.
Cayenne and Soap
Soap's active chemicals strip spider mites of their waxy coating, killing them through dehydration. The bitterness of soap also works alongside the cayenne pepper to serve as additional deterrent against future spider mite attacks. Add 6 drops of baby shampoo to 1 gallon of water and stir in 2 tablespoons of cayenne pepper powder. Allow this solution to set overnight before pouring the liquid into a spray bottle and applying to your plants.
Fresh Cayenne Peppers
Why stop at just cayenne pepper? Pair cayenne with jalapeno peppers for a potent punch of capsaicin. Boil 1/2-cup of dried jalapeno peppers and 1/2-cup of dried cayenne peppers in a couple quarts of water. Allow the pot to simmer for 30 minutes, and then remove the pot from the heat and allow it to cool completely. Pour the capsaicin water into a spray bottle and spritz it onto your plants.
Never apply your homemade soap or cayenne solutions onto your plants in the heat of the day or in full sun. During this time, plant tissues are more sensitive than usual and may be injured by the active chemicals in your herbs or soaps. Instead, treat your plants for spider mites in the early morning or in the evening. Additionally, this solution only works on contact. Thus, avoid overhead irrigation or using these homemade sprays during a rainy period, since it will reduce surface contact. Test the homemade spray on the foliage of one plant several days before applying to other plants, to monitor any damage. When handling and mixing hot peppers and sprays, always wear rubber gloves.
- University of California Integrated Pest Management Program: Spider Mites
- Colorado State University Extension: Chile Peppers for the Home Garden
- National Pesticide Information Center: Capsaicin General Fact Sheet
- Organic Gardening: All-Purpose Insect Pest Spray
- University of Florida Extension: Home Remedies for Insect and Disease Control
- University of Hawaii Extension: Home Recipes for Pest Control
- Clemson Cooperative Extension: Insecticidal Soaps for Garden Pest Control
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