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Five Gentle and Effective Ways to Get Rid of Garden Pests

Are insects eating more of your garden veggies than you? Before you start dousing your plants with industrial strength insecticide, consider what you might be introducing to your garden soil and, eventually, your stomach.

Originally developed as neurotoxins during World War II, organophosphate insecticides were first used commercially and residentially in the late 1930s. Since then, the use of many of these insecticides, such as DDT, has either been banned or heavily restricted due to its toxicity in creatures such as in fish and birds. As these were eaten by the next animal up in the food chain, the toxicity levels would increase until it started to reach levels that could potentially harm humans. This toxicity scare quickly brought the issue of finding safe yet effective insecticides to the forefront and commercial and hobby gardeners alike have since been experimenting with both new and age-old approaches to insect elimination.

Plant-based Pesticides

In 2009, during the 238th meeting of the American Chemical Society, a presentation was given by a group of Canadian scientists regarding the effectiveness of essential oils as pesticides, namely clove, mint, thyme and rosemary. The oils, they reported, have been effective in fighting aphids and mites, common pests found in crops such as strawberries and spinach. To use, farmers combine two or more of the oils and mix them with water before spraying on the crops.

Other natural insecticides such as pyrethrum and pyrethrin, which are extracted from chrysanthemums, are seeing a rise in natural insect prevention. In fact, chrysanthemums are often used as a companion plant in home gardens due to their effectiveness in repelling a wide variety of pests. One negative of pyrethrum use, however, is that it can also drive beneficial insects away from your garden.

Neem oil, another natural insecticide, is derived from an evergreen tree commonly found on the Indian continent. A tried and true insect repellent that has been used for hundreds of years, neem oil works by interfering with insect reproduction cycles and reducing their desire to feed. To use, blend about half a teaspoon of liquid soap with one quart warm water. Allow the soap to settle, and then add one teaspoon neem oil. Apply to plants every seven days during the morning or evening hours.

Diatomaceous earth is also a well-known natural insecticide that isn't plant-based at all; it's made out of the fossilized remains of algae known as diatoms. It works because of its physico-sorptive properties, which dehydrates insects by wicking the moisture out of them. To be effective as an insecticide, diatomaceous earth should be below 12 microns in size and not treated with heat.

Bug Eat Bug

When a ladybug lands on you it's considered good luck, and for good reason. Ladybugs are one of your garden's best friends. Their favorite foods include aphids, bollworms, potato beetles, leaf worms, leafhoppers and mealybugs, all of which are harmful to vegetable crops. Helpful garden insects don't stop with this bright little bug, however. Beneficial nematodes kill a plethora of harmful bugs, and green lacewings are great against slithery pests such as caterpillars, army worms and bollworms.

To attract ladybugs to your garden, try planting marigolds, fennel, dandelion, dill, butterfly weed or Queen Anne's lace. Lacewings also enjoy dandelion, dill and Queen Anne's lace, as well as caraway and coriander. Beneficial nematodes can be hard to attract at first, but they seem to enjoy tagetes and cover crops. You should also be able to purchase all of these bugs at a well-stocked garden supply store during the spring.

DIY Insecticides

You can also try making some insecticides of your own out of items around your house. Soapy water, for example, works by disrupting the cell membranes of insects and dehydrating them. Be careful not to add too much soap to the mix, however, as it can kill the vegetation as well. To make soapy water insecticide, use the following proportions:

1 Tablespoon liquid soap
1 quart water

For best results, spray in the morning or evening. If sprayed during the day, the sun might evaporate the water too quickly and the leftover soap will harm the plants. Additionally, you could add a drop or two of an essential oil to the mix such as clove, mint, thyme or rosemary as additional repellent.

Another homemade insecticide that works on slugs -- a common pest with soft vegetables such as lettuce, squash, carrots, peas and strawberries -- is beer bait. Simply bury some wide-mouth mason jars up to their necks near your most vulnerable plants and fill the jars with beer. The slugs will be attracted to the beer, fall in and drown. A sprinkling of diatomaceous earth around the perimeter of your soft vegetables can also help deter slugs; just remember to reapply after a rainstorm.

When all else fails, there's always the tried and true method of picking and pinching, or drowning, larger bugs. It may not be the most enjoyable pastime, but it doesn't involve chemicals and it's 100 percent effective on the ones you catch.

What are some ways you've found to fight garden pests naturally? What are some of your favorite recipes for fighting insects?


Mike Tuma is a Home Depot store associate in the Chicago area, where he has been helping customers since 2005. Mike focuses on outdoor living writing, ranging from tips on using a pressure washer to the latest in lawn mowers.