I really do not like to use chemicals in my garden, what are the other choices I can consider for pest control?

Instead of reaching for a synthetic insecticide to control those unwanted pests in the garden, try some more environmentally friendly options first. One pest management technique that is easier on our environment is mechanical control. Mechanical control is the use of hands-on techniques as well as simple equipment, devices, and natural ingredients that provide a protective barrier between plants and insects.

Exclusion Devices - Examples of exclusion devices include row covers, nets to keep birds away from ripening fruit, paper collars placed around stems of plants to prevent cutworm damage, and proper fencing or barriers to halt the spread of bermudagrass or to prevent pets and wild animals from damaging the garden.

Handpicking - Hand destruction or removal of insects and egg masses insures quick and positive control. This method is especially effective with foliage-feeding insects such as squash bugs, hornworms, and bean beetles. Excluding labor, handpicking is the least expensive of all organic or natural control practices. Disadvantages are that handpicking must be performed long before insect damage is noticeable and at the key stage of development of the insect. Gardeners must actively monitor their crops, watching for the first sign of damage before insect populations get too high.

Traps and Attractants - Mechanical traps and attractants are used in two ways: to trap enough insects to lower crop damage or to monitor how many and what species of insects are in the garden. Traps and attractants often appeal to an insect's needs for food, shelter, and reproduction.

A disadvantage of traps or attractants is that they may trap beneficial insects. Also, while some traps may be homemade using simple, inexpensive materials, others are expensive and must be cleaned or replaced periodically.

Water Pressure Sprays - A forceful stream of water will sometimes dislodge insects such as aphids and spider mites from foliage and plant stems. This practice must be repeated since many of the insects are likely to return.

Water pressure should be used only on sturdy plants to avoid plant damage. This method may also be a problem since frequent applications of water could increase diseases or could cause root problems if the soil is already too wet. Therefore, use water sprays in the morning so plants will dry out during the day.  We were able to control spider mites recently on the orange milkweed in the butterfly garden, just with a daily morning spray of water.

Diatomaceous Earth - Diatomaceous earth is composed of finely ground skeletons of fossil diatoms. Sharp edges of the ground diatoms scratch the waxy or oily outer layer of soft-bodied insects, which reportedly die eventually from dehydration.  The formulation of diatomaceous earth sold for swimming pool filters does not help control insects.

Diatomaceous earth is considered a pesticide, but is non-toxic to birds and mammals. Disadvantages are that it can kill beneficial insects such as lady bugs and it is less effective against pests in humid weather. Gardeners must wear a dust mask when applying diatomaceous earth to plants.

Insecticidal Soaps - Insecticidal soaps evidently kill insect pests by penetrating the insect's outer coat cuticle or entering the respiratory system and causing cell damage or disruption.

Several insecticidal soaps are distributed for control of insects and mites. Available under a variety of trade names, the active ingredient of all is potassium salt of fatty acids. Soaps are chemically similar to liquid hand soaps. However, there are many features of commercial insecticidal soap products that distinguish them from the dishwashing liquids or soaps that are sometimes substituted. Insecticidal soaps sold for control of insects:

  *   are selected to control insects;

  *   are selected to minimize potential plant injury; and

  *   are of consistent manufacture.

Certain brands of hand soaps and liquid dishwashing detergents can be effective for this purpose. However, there is increased risk of plant injury with these products. They are not designed for use on plants. Dry dish soaps and all clothes-washing detergents are too harsh to be used on plants.

One of the most serious potential drawbacks to the use of soap-detergent sprays is their potential to cause plant injury (phytotoxicity). Certain plants are sensitive to these sprays and may be seriously injured. The risk of plant damage is greater with homemade preparations of household soaps or detergents.

A short residual action means repeat applications may be needed at relatively short intervals (four to seven days) to control certain pests. Also, application must be thorough and completely wet the pest.

Environmental factors also can affect use of soaps. In particular, soaps (but not synthetic detergents) are affected by the presence of minerals found in hard water, which results in chemical changes. Control decreases if hard-water sources are used. Insecticidal soaps may also be more effective if drying is not overly rapid, such as early or late in the day.

Horticultural Oils - Oils are petroleum-based products containing certain fatty acids that form layers on plant parts to smother insects or provide a mechanical barrier to prevent damage. There are two kinds of oils: growing season (summer) and dormant.

For more information on these and other control techniques refer to HLA-6432<http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-2291/HLA-6432web.pdf> Earth-Kind Gardening Series: Mechanical Pest Controls.