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Less-Toxic Gardening and Landscaping - May 2005

May 31, 2005

UNIVERSITY PARK, Pa. -- Many homeowners want their lawns and gardens to be attractive and pest-free, but most don't realize pesticides can be misused resulting in harm to people, pets and the environment.

Many pest management mistakes are made by homeowners because they are not knowledgeable pest identification, life cycles and behavior. Moreover, homeowners tend to look for 'silver bullet' solutions when the best solutions usually involve the combination of activities that add up to keeping the pests at bay.

An integrated pest management (IPM) approach to pest management that considers many different methods simultaneously provides the most effective way of suppressing pests in the lawn and garden, while assuring the safety of children, adults and pets alike. A pest can be anything from ants in the kitchen, weeds in the lawn, a fungus on the trees to a deer in the garden. IPM is a safe, economical and step-wise approach to pest management. It integrates knowledge of pest identity and biology with pest monitoring so that actions, if any, can be taken at just the right time. In addition, IPM uses a combination of management tactics that are more likely to be safe and effective. While pesticides (bug sprays, weed killers, etc.) can be used as part of an IPM program, it is a good idea to limit their use and thereby, your exposure. Pesticides should be used only as a last resort and carefully chosen, carefully used, carefully stored and carefully disposed of.

Resorting to pesticides without full knowledge of your target pests and/or the chemical properties of the pesticide can lead to unnecessary, ineffective or downright dangerous use of chemicals. In fact, home and garden pesticide applications account for more pesticide use on a per acre basis than agriculture. In the United States, non-farmers use over 163 million pounds of pesticide active ingredient, spending over $2.1 billion per year ($7.50 for every woman, man and child). Ask yourself: Do I really need a chemical to solve this pest problem? If so, which is the least-toxic choice?

In the garden, try these IPM tips (adapted from the New York IPM Program):
- Grow pest-resistant plants. Choices should be well suited to soil and climate.
- Use selective pesticides. Insecticidal soaps are effective against aphids, mealybugs, whiteflies, scale, and some other pests. Bacillus thuringiensis or "Bt" is a bacterium that kills leaf-eating caterpillars and other specific insect and is sold in garden stores.
- Grow healthy plants. Pay attention to organic matter, watering, and other conditions for healthy plants. - Don't grow closely related plants (e.g., tomatoes, peppers, eggplant) in the same location each year. - - Rotation prevents insect infestations, decreases the spread of diseases, and lessens the depletion of soil nutrients.
- Encourage beneficial insects, which kill pests, by growing large, showy composite flowers for them to land on and feed (such as Queen Anne's lace, daisies, fennel, dill) and by limiting pesticide applications.
- Destroy diseased plant materials, and clean up plant debris at the season's end.

In the landscape (adapted from the New York IPM Program):
- Grow pest-resistant varieties of plants, shrubs, and trees. Choices should also be well suited to soil and climate.
- Grow healthy plants. Pay attention to organic matter, watering, and other conditions for healthy plants.
- Avoid injury to tree trunks (from mowers, weed whackers) that enable pests to gain footholds; lay mulch at tree bases.
- To combat weeds, maintain an adequately fertilized lawn; hand dig weeds; spot- treat.
- Use selective pesticides. These will kill only your target pest while leaving non- target species unharmed.
- Encourage beneficial insects--which kill pests--by growing large, showy composite flowers for them to land on and feed (such as Queen Anne's lace, daisies, fennel, dill) and by limiting pesticide applications.
- Clean up plant debris at the season's end and destroy diseased plant materials.

Do not be tempted to spread broad-spectrum insecticides over your lawn on a calendar basis as "insurance" against all bugs. Broad-spectrum insecticides will kill far more beneficial insects in your lawn than the pests you are trying to keep in check. You may create more pest problems than you solve by this approach, and contribute to contamination of surface water runoff and kill non-target organisms. Target only the pest you know you have, when you have it, causing actual significant damage.

If you do use a chemical as part of the solution for a pest problem, seek information on the least-toxic, most effective alternatives from your County Cooperative Extension office, Master Gardeners or other trusted sources. In addition, if you decide to hire a lawn care company, you should be aware of the practices and products they are using on your grounds, why and when.

Questions to ask your lawn care company technician:
-·Have you found any pests in my lawn (insects, mites, disease, weeds)? Can you show me?
- How do you assess a lawn for pest problems? Are there enough of each pest species to worry about?
-·Are there any lawn care maintenance practices that I can employ to minimize pest damage such as different mowing practices, irrigation, soil amendments, etc?
- Do you have a pesticide-free lawn care program?
- If you decide to apply a pesticide (insecticide, fungicide, herbicide) can you tell me why?
- What will happen if you do not apply the pesticide?
If the technician cannot answer these questions, then switch companies. It is a very competitive industry.

For more information on less-toxic home gardening and landscaping, visit the Pennsylvania IPM Program's Web site at http://paipm.cas.psu.edu and click on and click on "Home & Garden" IPM. Visitors will find more IPM tips, publications and the "Home and Garden Pest Problem Solver", which allows homeowners to quickly find information on their pest problems.

The Pennsylvania IPM program is a collaboration between the Pennsylvania State University and the Pennsylvania Department of Agriculture aimed at promoting integrated pest management in both agricultural and nonagricultural situations. For more information, contact the program at (814) 865-2839, or visit Web site http://paipm.cas.psu.edu. To view our archived news releases, see Web site http://paipm.cas.psu.edu/newsrelease.html.