From: National Wildlife Federation
Published March 23, 2005 12:00 AM

Organic Gardening Basics: Eliminating Pesticides and Fertilizers

Eliminating Pesticides


In the natural world, virtually everything is sought out and "eaten" by something else. In the American garden, insecticides, fungicides and herbicides often take the place of healthy soil and mechanical and natural controls. Pesticides are meant to kill. If there is a safe pesticide, it is one that kills only the target organism and leaves no trace in the environment. Few pesticides meet these very selective criteria.


What you can do:


* Select and maintain pest-resistant plants adapted to your area - native plants generally have few pest problems.
* Use organic gardening techniques - healthy soil building techniques, companion planting, herbal pest sprays, and crop rotation.
* Learn to recognize and care for natural pest controls, such as ladybird beetles, beneficial wasps of many sizes, birds, toads, parasitic and predatory flies, and many others.
* Intervene if you must. Try hand removal or spraying pest insects with water. If this fails, try biological controls, traps, or a dust such as diatomaceous earth - a silica substance that kills soft-bodied insects such as aphids.
* If you must use pesticides at all, use them with proper handling and safe disposal methods. Start with the least toxic type, such as an insecticidal soap. Steer clear of broad spectrum insecticides, such as SEVIN or DIAZINON. Contact with these chemicals will kill virtually any invertebrate.
* Control weeds through appropriate fertilization and liming, adjusting mowing height, and mulching.
* When you pitch your pesticides, dispose of them properly through a municipal or county toxics disposal program.


Eliminating Fertilizers


Most commercial fertilizers boost plant growth rapidly. Too commonly, these high potency fertilizers are used in excess, and end up as phosphorus and nitrate pollution of ground water and small streams. Poisoning of aquatic life and severe oxygen deficiencies may result from these chemicals reaching our water sources.


What you can do:


* You can reduce fertilizer potency and application rates and still improve plant health. "Natural" fertilizers, such as composts and pasteurized manures, are preferable, as they release a much greater variety of nutrients more slowly.
* If commercial fertilizers are used, choose a slow releasing fertilizer.
* Make and use compost in the landscape and save landfill space.
* Plant cover crops like buckwheat and clovers. These plants add or "pump up" nutrients to the root zone and physically improve the soil.
* Try composted sludges, which are derived from sewage or industrial processes. Request a fact sheet listing possible contaminants before purchasing or applying composted sludge to be sure it does not contain heavy metal or chemical contamination.
* Grow native plants. Many native plants will grow very well with only an annual application of leaf mulch or with an annual cultural practice, such as mowing or burning.


Organic Pest Control Tips


Prevention:


* Talk with your neighbors about not using chemical pesticides.
* Plant native plants which can hold their own against native pests.
* Build healthy soil to have strong healthy plants - compost.
* Gradually eliminate plants that always get sick - they are probably not native.
* Weatherstrip your house at windows and doors to keep pests out and heat/ac in.
* For aphids, do not over fertilize with nitrogen because they seek fresh plant growth.
* Attract birds to your yard by planting appropriate plants.
* Prune and destroy infested wood.
* Remove garden debris like old boards so slugs don't have a wet spot to live.
* Get to know your beneficial bugs and don't hurt them!
* Craneflies and moles live in the lawn, so reduce your lawn size.


Physical Barriers:


* To reduce ants indoors, the cat food bowl can be smeared with a thin band of petroleum jelly at its base to keep ants from gaining access to it. NEVER feed pets outside.
* Spray plants with a strong stream of water to knock aphids off.
* In spring, trap gypsy moth caterpillars by wrapping burlap around trunk of tree. Destroy caterpillars from this shelter every afternoon.
* To reduce ants on trees and plants, put a sticky barrier such as teflon tape. (Ants are usually protecting the aphids because they like to eat something called "honeydew" which the aphids produce.)
* In vegetable gardens, put netting ("floating row covers") over vegetables to reduce egg-laying by insects. Floating row covers consisting of lightweight, fine-meshed fabric can be loosely draped over crop rows and anchored to the soil at the edges. The small mesh size excludes nearly all insects the size of aphids or larger. For regular habitat gardening, avoid using this netting as it can entangle wildlife, especially snakes.
* Slug traps: covered plastic containers such as yogurt or margarine tubs baited with fresh beer sunk in ground, leaving one inch of rim exposed; renew every three to four days.
* In vegetable gardens, weed and turn your soil. Some weeds serve as a reservoir for insects such as flea beetles, spinach leafminers and aphids that may later move to garden plants. Regular cultivation will expose soil insects to predators, parasites, and weather. Plow or spade gardens in the fall to incorporate compost into the soil and expose soil pests. For regular habitat gardening, it is often not a good idea to turn the soil as disturbed soil is a haven for non-native plants.
* Removing insects by hand can effectively control small populations of pests such as potato beetles or cabbage loopers.


Biological/Chemical Tips:


* Moles: Put one ounce of liquid dish detergent and two ounces of castor oil in a blender. Whip them until the mixture holds its shape. Add six tablespoons of water and whip again. Fill a watering can with water and add two tablespoons of the castor oil mixture. Apply to the areas of heaviest tunneling. This works well after a heavy rain or watering.
* For aphids, use mild soap spray or homemade garlic spray.
* To control aphids and spider mites, use horticulture oil and spray on trees when they are in their dormant stage (late fall).
* For slugs, hand-pick them, drop in soapy water, hunt at night with a flashlight; scoop up and dispose of pearl-like egg clusters to reduce populations.
* Beneficial nematodes help with root weevils, fleas and craneflies. Follow product directions.
* Bacillus Thuringiensis, commonly referred to as "B.t.", is marketed under the trade names Dipel, Thuricide and others. This "microbial" insecticide consists of spores and crystals produced by a soil-inhabiting bacterium. When certain insect species ingest these spores and crystals, the digestive tract becomes paralyzed and the insects stop feeding, become sick, and die in four to seven days. This is especially useful for controlling cabbageworms and a few other species of caterpillars that damage garden crops.


Do NOT:


* Use traps to kill moles. Moles don't eat plants, but rather earthworms -- or beetle grubs that can damage lawns. Reduce your lawn instead.
* Do not worry about killing tent caterpillars in a habitat garden. These are native species that typically don't do long-term damage to their host plants, which are limited to cherry, apple and pear species.
* Do not put weeds or diseased plants in your compost pile because the temperature might not be high enough to kill them and then you'll spread them out again.
* Do not introduce ladybugs or other predator bugs. Doing this properly requires a keen knowledge of predator/prey relationships and most of the insects you purchase are non-native.
* Be wary of methods which suggest boiling plant parts or grinding them up in a water solution to use as a spray on vegetables. This spray solution can be very poisonous. For example, boiling rhubarb leaves or soaking tobacco stems in water is apparently practiced by some gardeners. Both of these plants contain extremely toxic poisons and should be dealt with carefully.


Related Link: National Wildlife Federation's Backyard Wildlife Habitat Program


Source: National Wildlife Federation


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