Pepper as a pest repellent has been used for generations in home gardens, though until recently it was dismissed by many as an old folk remedy. The increased awareness of organic gardening methods today is causing more gardeners to take this remedy seriously. If you want to control pests without toxic chemicals, you should take it seriously too.
Pepper is effective in repelling insects and other garden pests because of a chemical called capsaicin. Capsaicin irritates the eyes and skin of animals, insects and people. It tastes bad to some pests, making the host plant unappealing. It is important to note that pepper repellents are just that--repellents. They do not kill garden pests; they do discourage them from munching on your plants.
Capsaicin can irritate your skin and eyes, so use caution using products or homemade sprays with this ingredient. Wear gloves and eye protection. There is a reason that law enforcement agencies use pepper spray to stop people--it works!
Types of Peppers
Capsaicin is found in various types of peppers. Those most commonly used include chili, cayenne, red or black pepper and paprika. Some products have been developed using the habanero pepper. Habaneros are known to have extremely high concentrations of capsaicin.
Commercial products can be purchased with capsaicin as an active ingredient, or you can make your own using fresh or dried peppers. Purchase pepper from the grocery store or grow your own.
Pepper does not repel every garden pest, but it is effective on many of the most common ones. Insects that avoid pepper-sprayed or dusted plants include aphids, grasshoppers, thrips, leaf miners, white flies, lace bugs, caterpillars and scale.
A mixture of pepper, garlic and soap or oil may repel raccoons, deer and rabbits. Keep in mind that animals respond differently depending on the location or situation. While some of these critters may run for the hills at the first whiff or taste of this concoction, others may think it makes a lovely salad dressing and continue to dine. Be willing to experiment a bit to see what works best in your garden.
Studies conducted by the Alabama Agricultural Experiment Station have shown that red pepper, garlic and other organic materials are effective in the control of cabbage loopers and other caterpillars that tend to damage cole crops like cabbage, broccoli and kale. In their studies, liquid soap was added to the garlic-pepper mixture to ensure even coverage on the plants.
A fact sheet on capsaicin from the EPA states that it is useful for repelling birds, rabbits, squirrels and even dogs. While most commercial preparations state that the pepper product is for use on ornamental plants, the EPA fact sheet says it can also be used on fruit and vegetable crops. If you purchase a commercial product, follow the directions carefully for best results.
The Capital City Garden District of New York recommends using pepper, either as a spray or as a powder sprinkled on the ground, to protect seedlings from chewing pests.
Make Your Own
If, like many gardeners, you prefer to make your own pepper repellent, there are a few different ways to do it. Feel free to experiment until you find a mix that works well for you.
You can use a purchased dried pepper, such as cayenne pepper, or you can dry and grind your own fresh peppers from the garden. Mix a half cup of pepper into a pint of water and allow to sit for a day. You can add a few drops of dishwashing soap or Castile soap to this mix for better coverage and sticking quality. Vegetable oil works well for this also. Spray this mix on the leaves of susceptible plants, preferably before they become infested with insects.
Another recipe from the book "Carrots Love Tomatoes & Roses Love Garlic" by Louise Riotte mixes peppers, garlic and onion in enough water to cover. Let it sit for 24 hours, strain it, add enough water to make one gallon, and use the spray on leaves. Save the strained residue to sprinkle on the ground around your ornamentals.