Haven't read everything fully to comment on, but wish to share this link that I've come across.

Joe


http://www.chron.com/disp/story.mpl/gardening/urbanharvest/5785260.html

May 17, 2008, 12:23PM
Pest management remedies from the kitchen

By MARK BOWEN
Urban Harvest

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When considering a product to aid in pest management, it is important to treat with the mildest product that will do the job while being the least disruptive to beneficial insects and the least-toxic to people. It often makes sense to wait a little while before treating to see if beneficial insects will do the job for you. The Texas Bug Book by Howard Garrett and Malcolm Beck and the Insect Color Handbook by Anna Carr are two helpful books for insect identification.

Over the long term, gardeners will reap great dividends from planting a variety of native and well-adapted naturalizing plants. Many of these plants such as wild ageratum, butterfly weed and native asters will attract them in droves while others like black-eyed Susan, scarlet sage, Indian blanket, Gulf Coast penstemon, bee balm, gayfeather, Mexican hat, and verbena will provide the nectar to feed the adult form of many beneficials. Before you know it, the beneficials will visit other plants in your landscape and help keep populations of pests like tomato hornworms, spider mites, aphids, whiteflies, webworms, tent caterpillars and others in check.

In order to keep the beneficials in play, it is necessary to hold off on using harsh, toxic chemical and organic pesticides in and around the landscape and garden. These days, we have so many least-toxic organic options available, that the need for the old toxic treatments is simply moot.

The following are a few homemade pest management products that are easy to use effectively and safely when transitioning to a more ecological approach to pest management. Over time as you stop using harsh pesticides, as you start planting natives, and as you stop using pest prone plants, you will find that it becomes rare that even least-toxic treatments are needed.
Water

Targets: aphids, mealybugs, thrips and spider mites.

A blast of water from the hose is often enough to kill a large number of soft-bodied insects.

Liquid Soap

Targets: aphids, mealybugs.

Dish soap can be used at the rate of one to three teaspoons per gallon of water to help manage most soft-bodied pests. The soap breaks down the structure of their exoskeletons and causes them to dry out to the point of death. It is often advisable to test spray small sections of plants to make sure the foliage will not be too sensitive to soap. Washing off soap residue an hour or so after application can help reduce plant sensitivity. Plant based, fatty acid soaps such as Shaklee or Life Tree are less likely to cause sensitivity than petroleum based dish soaps.

Soybean Oil

Targets:scale, whitefly and other pests.

Soybean oil has proven to be nearly as effective as petroleum dormant and summer oils in minimizing scale, whitefly and other pests. Soybean oil has the added benefit of being less likely to burn plants or cause skin irritation to applicators than petroleum oils. Soybean oil can be used at the rate of 4-7 tablespoons per gallon of water as a summer oil to smother whiteflies. It can also be used at the rate of 7-10 tablespoons per gallon as a dormant oil to minimize scale.

Citrus Oil

Targets: fleas, chinch bugs, scale, thrips, fire ants and other insects.

Citrus oil is produced by cold pressing or boiling citrus peels to extract the oils that are rich in d-limonene and linalool. These citrus compounds have proven to be effective against fleas, chinch bugs, scale, thrips, fire ants and other insects. The citrus peels from two to three large oranges can be cold-pressed or blended long enough to generate enough oil to add to one gallon of water after straining if blending has occurred. Plants can be sprayed as needed to minimize pests, or the solution can be used as a drench (drench deeply) on fire ant mounds. Chinch bugs will require a few treatments to minimize their populations adequately in conjunction with improved management practices including adequate watering and sufficient mowing heights. Scale will require periodic treatments to minimize their populations. Keep in mind that eradication of scale is not possible over the long term on scale-prone plants even when harsh products are used, so minimization and the possible eventual replacement of susceptible plants is often a realistic goal.

Garlic Oil

Targets: spider mites, mosquito larvae, lacebugs, black spot, powdery and downy mildews, fungal leaf spot.

Garlic oil can be made in the kitchen by blending 2-4 full garlic bulbs, by straining out the solids and then adding the liquid to one gallon of water. The sulfur compounds (diallyl disulfide and diallyl trisulfide) have been shown in trials to be effective as tools for managing spider mites, which are highly susceptible to sulfur compounds. The sulfur compounds found in garlic oil are also helpful for minimizing black spot, powdery and downy mildews as well as fungal leaf spot. Adding a teaspoon or two of soap to garlic oil will increase its effectiveness against the listed leaf diseases due to the fungicidal properties found in soap as well. Garlic oil will also kill mosquito larvae and will slow down lacebugs (not to be confused with the beneficial lacewings).

Pepper Tea

Targets: spider mites, lacebugs, other insects and used in animal training.

Two to four hot peppers such as cayenne, jalapeño, habañero or other hot peppers can be blended, the solids can be strained out and the liquid can be added to a gallon of water to make pepper tea. Pepper tea can be combined with garlic oil and sprayed on plants to keep spider mites, lacebugs and other hard to manage insects in check. Gardeners often use pepper tea as a short term repellant when training animals to stay out of certain garden areas. Be sure to wear goggles when spraying pepper tea.

Keep in mind that while the homemade pest management remedies listed in this article are generally considered mild in nature, it is recommended to wear protective eyewear and clothing to prevent any allergies or other reactions from occurring.

Also remember that all products, including homemade remedies can kill or repel beneficial insects. Products should be used as selectively as possible rather than on large areas as preventive measures to avoid unnecessarily disrupting the insect ecology of your garden or landscape.

All of the remedies listed are also available under brand names at numerous nurseries and garden centers.

Mark Bowen is a local author and the staff horticulturist for Urban Harvest. This column is produced by Urban Harvest. For information about community gardening, gardening classes, volunteer opportunities or farmers markets visit www.urbanharvest.org.