Beware of Homemade Brews

We have had some inquiries about "homemade brews and tonics" used for garden pest control, as recently espoused by a well-known popular gardening personality on radio and TV. Some of the mixtures described include things such as vegetable oil, dish soap, vinegar, mouthwash, tobacco juice, alcoholic beverages, laundry detergent and even human urine. A call recently inquired about the rate to mix one of these homemade brews and how to apply it through a hose-end sprayer. Of course, Extension does not have rates and information on how to use these homemade brews, because we do not endorse them for pest management. As far as we are concerned, none of these items are labeled for use in pest management and therefore they are illegal to use, not to mention that they probably don’t work and can injure plants. As far as we know, there is no scientific research information presented by this gardening personality to show that these mixtures are, in fact, effective in pest management.

Anytime you use an unlabeled product or mixture of products for pest management, you are acting on your own and must take responsibility for any plant damage that arises. We have heard from several gardeners who have tried such homemade brews and have damaged or killed plants. Several of the recipes include high rates of vegetable oil and dish soap; far above what is labeled in commercially available horticultural oils and insecticidal soaps. We know that plants can be damaged if these products are used at high rates and/or if they are used incorrectly.

In the past few years, Extension has promoted an integrated approach to managing plant pests. Pesticides are included in this approach, often as the last resort. Many times, cultural methods and taking advantage of natural predatory insect populations will go a long way in avoiding or limiting a pest population. Homemade mixtures of common household items (which are chemicals in their own right) are not the answer to pest control and homeowners are cautioned to think about what they are doing before mixing one of these to use in the garden.

Source: Ohio State University

Return to August Garden Calendar