Start with a little chopped garlic. Add equal parts onion, hot pepper, horseradish and vinegar. No, you’re not whipping up a lovely Italian meal; it's something better: a natural pesticide.
Bugs and other pests don’t like it hot and spicy. So if you’re looking for natural alternatives to the synthetic pesticides that you often find at the store, try using nontoxic household substances already in your pantry.
Ingredients such as garlic, salt, peppers, baking soda, orange peels and cooking oils can be found in many homemade pesticide recipes. Herbs, seasonings and other food products also are contained in the commercial pesticides sold at home improvement stores.
Since the vast majority of garden pests are beneficial to plants, genuine organic pesticides — applied properly — can ward off harmful critters without damaging the environment.
Use plants to your advantage
Bugs are attracted to most plants because of their fragrance. It makes sense, then, that they’d be turned off by foul-smelling garlic, tobacco or even basil, sage, chives and rosemary.
Let’s consider garlic. Organic gardeners have long known garlic is an odorous repellent to pests. Planting garlic between rows of vegetables or roses will repel aphids and other insects, according to West Coast Seeds, which offers a comprehensive list of companion plantings to ward of the bugs you don't want.
If you don't have room for companion plants, a number of recipes for garlic sprays combine mixed garlic or garlic powder with other products such as mineral or vegetable oils, onions, peppers, even dishwashing soap, another popular bug-zapper.
Garlic sprays work on aphids, cabbage loopers, June bugs, leafhoppers, squash bugs and whiteflies, reports Comfy Country Creations, a Canadian-based website offering gardening tips and homemade bug spray recipes.
A factsheet from the Sonora Environmental Research Institute in Tucson suggests citrus oil or cayenne pepper as pesticide alternatives.
Try plant substances and extracts
The garden itself offers a host of natural pesticide options.
The dried, powdered flowers of the pyrethrum daisy have become a popular insecticide ingredient. Not to be confused with pyrethroids, a new class of synthetic pesticides, pyrethrins are concentrated in the seeds of the flower head.
Pyrethrins are considered a contact insecticide; insects merely touching the substance are affected. The product only works on certain insects such as flies, gnats, mosquitoes, spider mites, leafhoppers, stink bugs and aphids. Mix the dried powder with water and a few drops of liquid soap and you can use it to protect other flowers, fruits and vegetables, Comfy Country Creations reports.
A commercial brand that uses pyrethrins is Safer Yard and Garden Insect Killer Spray.
And don't forget the simplest solution first: Try using a 1 percent solution of a simple dishwashing soap with water first. When considering commercial insecticides, opt for those made from naturally-occurring plant extracts. For example, Orange Guard Home Pest Control Spray, which is OMRI Listed, uses steam-distilled orange peel oil to kill cockroaches, ants, fleas, locusts and weevils. (OMRI is the Organic Materials Review Institute, which offers an independent review of products to see how they match up to organic standards.)
As with all pesticides, research first whether the bugs you're trying to destroy are harmful or not, take note of the product’s intended use, test it on a single plant to determine its effect, and only spot-treat targeted plants and bugs. Also, know your ingredients and watch how your landscape and the creatures in it respond to the new addition. As the Backyard Conservation Fact Sheet of the U.S. Department of Agriculture’s Natural Resources Conservation Service, points out, even some organic pesticides may be just as toxic as the synthetic chemical products if they are used incorrectly or in large doses.
The NRCS fact sheet also lists beneficial insects, the bugs they control and natural pest management strategies. Again, start with the easiest attack first. Simple solutions include spraying water from a hose to remove insects and applying a baking soda solution to control fungal diseases on roses.
For more information about choosing the least-toxic pest control products and other pest management tips, consult the National Pesticide Information Center (NPIC).
Editor's note: This story was originally created in March 2011 and has been updated with additional information.