Limit Your Exposure To Pesticides
When most people think of pesticide use, they think of agricultural land. But pesticides typically are applied at much higher rates to residential landscapes than to farms-20 times higher, according to the U.S. Environmental Protection Agency (EPA).
The enormous quantity of pesticides used in home landscapes raises a number of health and environmental concerns, starting with the potential for accidental poisonings of humans and pets. The possibility of cancer or other illnesses as a result of nonaccidental, chronic exposure to yard pesticides is the subject of an ongoing scientific debate. Children and fetuses, whose internal organs are still developing, are particularly vulnerable to the health problems pesticides may pose. Although pesticides and their use are regulated by the EPA, the uncertainty over the long-term effects of exposure to even low levels led the American Medical Association to recommend that we limit exposure to these chemicals and use safer alternatives.
Overuse of pesticides is contributing to the chemical load not just in our bodies, but in the environment at large. It's estimated that 5 percent or less of the insecticides and herbicides we spray ends up on the target pest. The rest ends up on plants, in the soil, and in the air-and via drift, it can also land on any nearby people or pets. Pesticides in runoff find their way into drinking water supplies and local waterways; pesticide pollution was found in every stream and over 90 percent of the wells sampled in a study by the U.S. Geological Survey. In waterways, pesticides can kill fish and other aquatic life. It's believed that pesticides kill millions of birds each year, and can impair the ability of others to reproduce. They've been linked to the decline of frog populations, as well as earthworms and other important soil animals. They've also led to the loss of pollinators and the beneficial insects that would otherwise help keep pest populations in our landscapes in check.
What To Do
- One of the best ways to minimize your exposure to pesticide residues in food is to grow some herbs, vegetables, and fruits at home, avoiding the use of toxic and persistent chemical pesticides.
- Use one of two proven systems, organic gardening or integrated pest management, to eliminate or drastically reduce the amount of pesticide you apply throughout your landscape. If you hire a company to care for your lawn or garden, make sure it is one that employs these least toxic approaches.
Organic Gardening
It's generally known that organic gardeners refrain from using synthetic fertilizers and pesticides on their plants. But organic gardening is a lot more than that. It promotes and enhances natural diversity and biological cycles to make the garden self-sufficient and sustainable, beginning with building and maintaining soil fertility by adding compost and other organic matter. See Soils for ideas on how to get started. The second key to successful organic gardening is choosing plants suited to your climate and the growing conditions on your property, because these are best able to grow without a lot of added water, fertilizer, and drastic pest controls.
Organic gardeners employ a variety of other common-sense techniques when necessary to keep their plants healthy. Most of these involve good growing practices that help prevent pest outbreaks, and outsmarting potential pests before they overwhelm plants rather than simply blasting them with toxic chemicals. Let's say you're in the vegetable garden and notice that one of your bean plants is being chewed to bits. What do you do? First, you examine the plant carefully for signs of the pest. More times than not, you can solve the pest problem the minute you see it, by picking it up and crushing it or dropping it into a container of soapy water. There are many other so-called physical controls as well, from simple, 3 inch-tall collars made of cardboard or newspaper placed around plants to keep out cutworms, to rowcovers, thin and lightweight fabrics developed in the past few decades that let in rainfall and plenty of sunlight for growth but are impenetrable even by tiny insects.
Organic gardeners also make their landscapes havens for the natural predators of plant pests. Many homeowners have pest problems at least in part because their yards are not inviting to so-called beneficial insects, the tigers and barracudas of the insect world which in natural ecosystems keep herbivorous insects in check. Although a number of biological pest controls, the fancy term for beneficial insects, are sold at local nurseries and by mail-order suppliers, the most effective way to attract predators to your yard is to grow asters, coneflowers, and other daisylike native wildflowers, as well as popular culinary herbs such as dill and parsley that produce inverted parasol-shaped inflorescences.
Organic gardeners use natural alternatives to synthetic pesticides, including biological controls such as Bacillus thuringiensis (Bt), a bacterium that occurs naturally in soils around the world. Different strains of Bt produce toxins that affect different insects, including the caterpillars of gypsy moths, hornworms, and cabbage worms as well as the Colorado potato beetle and other leaf beetles. Insecticidal soaps applied as dilute sprays (1 to 3 percent concentration) are especially effective against small, soft-bodied species such as aphids and spider mites. Botanical insecticides such as sabadilla and neem, which are derived from plants, are sometimes used as a final resort. Botanicals can be toxic and must be handled with caution, but most do less ecological damage than synthetic pesticides because they break down relatively rapidly when exposed to heat, light, or water.
If you're just starting out as an organic gardener, a basic guide to organic growing techniques is a good investment. Organicgardening.com, the website of Organic Gardening magazine, has a wealth of useful tips. The Organic Materials Review Institute website includes the OMRI Products List, a directory of all products the organization has determined are allowed for use by organic growers.
Integrated Pest Management
Integrated pest management, or IPM, is another commonsense approach to pest control that includes many of the techniques used by organic gardeners but does not rule out the use of synthetic pesticides as a last resort. Although it was developed initially to help commercial farmers avoid spraying on a regular schedule whether it was necessary or not, it has been adapted for home gardeners and can be effectively employed with or without the use of synthetic pesticides.
IPM is a systematic process involving prevention, monitoring, and choosing the least toxic pest control when action is necessary. One of its fundamental principles is that not all insects and weeds require control. Many are innocuous, and some are even beneficial. Another is the recognition that when it's advisable to intervene, the goal is pest control, not eradication.
Monitoring your plants as often as possible throughout the growing season is the cornerstone of IPM. When you do encounter a pest problem, you need to learn about the extent of the damage it can cause, and what will happen to the plant with or without treatment. Seeing a single pest doesn't mean that action must be taken-you should continue to keep a watchful eye on your plants, and decide how much damage is acceptable.
As in organic gardening, taking steps to prevent pests from becoming a problem is another basic IPM practice. This may mean using cultural practices, such as keeping your planting beds clean of any infected plant material, moving vegetables to different areas of the garden annually to prevent a build-up of pests that live in the soil, or planting a variety of flowers that provide pollen and nectar for beneficial insects.
If you determine that action against a particular pest is essential, the next step is finding the least toxic yet effective way to deal with the problem. Physical controls, such as picking the pests off your plants by hand, blasting them with a strong stream of water to wash off pests like aphids and mites, or protecting them with row covers, are the first options to consider. Biological controls like Bt can provide control with minimal impact.
If chemical control is the only solution to your pest problem, the goal is to spray with the least toxic and most pest-specific product available before resorting to more toxic and persistent synthetics. These include insecticidal soaps and Neem-based or other naturally derived pesticides. Unlike products designed to target the pest you're trying to control, broad-spectrum pesticides destroy both harmful and beneficial insects. Not surprisingly, the pests re-establish themselves a lot faster than the beneficial species.
For more information on the best IPM controls for your area, contact your state or local Cooperative Extension office.
