Ways to reduce pesticide use in garden
Home gardeners often use more pesticides per square foot in their gardens than farmers do in the fields, thinking that if a little is good, more will be better.
This is a serious mistake and a misuse of pesticides.
Pesticide overuse has a number of adverse effects:
It makes food less safe to eat, especially if there are residues at harvest time.
It makes handling plants dangerous.
It may harm or kill beneficial insects, earthworms, birds and pets.
Each time gardeners spray, they are exposed to dangers of inhalation or absorption of the toxin. Pesticides may leach through the soil into groundwater and contaminate water supplies. Pesticides used near ponds may kill aquatic life.
Continuous use of certain pesticides may induce resistance in pests, requiring the use of more toxic substances. Some pesticides break down slowly and can remain in the environment for years.
Because a home gardener does not have to live up to perfect market standards, pesticide use may be reduced to a minimum with a little research and effort.
If the choice is between minor insect damage and possible pesticide residue, consider accepting the visible blemish that can be removed. Proper soil preparation, careful plant selection, and good garden practices can be combined with biological and mechanical controls to reduce the need for conventional chemical control.
Maintain a slightly acidic soil (around pH 6.5). If in doubt, purchase a soil test mailing envelope from the Extension Office for analysis done through The Pennsylvania State University.
The appropriate pH allows vegetable plants access to all the necessary soil nutrients and provides a suitable environment for earthworms and microorganisms. Till the soil in the fall to expose pests that live near the soil surface to natural enemies and weather and to destroy insects in crop residues. If you do not till in the fall, do so early enough in the spring to give remaining vegetation time to degrade before planting time.
Plant crops suited to the soil and climate of our area. Use disease-free, insect-free, certified seed if available. Select disease- and insect-resistant or tolerant species and varieties. Select plants that are sturdy and have well-developed root systems.
The most effective and important of all practices is to observe what is going on in the garden. Many serious pest problems can be halted or slowed if you visit the garden regularly for the purpose of inspecting plants.
Here are more tips for reducing or eliminating pesticide use in your garden:
Do not grow the same kind of produce in the same place each year. Use related crops in one site only once every three or four years.
Avoid placing plants of one kind together. Alternate groups of different plants within rows or patches. If an insect lays eggs or otherwise attacks a particular species, the presence of other species in the area can interrupt progress of the attack by diluting the odor of the preferred plants. This can also slow the spread of diseases and pests, giving you more time to manage them.
Thin young plants to a proper stand. Overcrowding causes weak growth and subsequent insect and disease problems.
Water in the morning, so plants have time to dry before the cool evening when fungus infection is most likely. To prevent spreading diseases, stay out of the garden when plants are wet. For plants susceptible to fungus infections, such as tomatoes, leave extra space between plants to allow good air flow.
Time plantings in such a way that the majority of the crop will miss the peak of insect infestations. For example, plant squash as early as possible to avoid borers, which lay eggs in July.
Remove infected leaves from diseased plants as soon as you observe them. Dispose of severely diseased plants before they contaminate others. Clean up crop refuse as soon as harvesting is finished.
Staking or planting in wire cages prevents the fruit from touching the soil. It also helps prevent fruit rots.
Caging helps reduce sun scale often seen in staked tomatoes, since caged plants do not require as much pruning, leaving a heavier foliage cover.
Boards or a light, open mulch such as straw, placed beneath melons, will prevent rotting.
Use a mulch to reduce soil splash, which brings soil-borne disease into contact with lower leaves.
Control weeds and grass. Weeds often harbor pests and compete for nutrients and water. They provide an alternate source of food and can be responsible for pest build-up.
Weeds also provide cover for cutworms and slugs. Inspect plants for egg masses, bean beetles, caterpillar and other insects often. Handpick as many as possible.
"Growing Green" is contributed by Lehigh County Extension Office Staff and Master Gardeners. Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-746-1970.