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Natural Insecticides For Your Garden
Savvy gardeners can use natural insecticides (Organic Insecticides) to curb problems caused by overly enthusiastic six legged munchers in their gardens. You must ensure, before you deploy any insecticides, that you have reached the insect damage threshold and that applying the insecticides is worth it. Remember too, we gnomes also live beneath your garden. We are not immune to poisons either. I would rather eat an ear of corn or an apple that has a little worm damage that I can see, than swallow a dose of poison I cannot.
Before You Apply Even A Natural (Organic) Insecticide
When you apply insecticides, you not only destroy harmful insects, you also destroy beneficial insects. That does not mean that using insecticides is a bad idea, it just means that you need to be certain that your insect problem meets the following four criteria before you treat:- The insects are inflicting lasting, permanent damage
- The insects cannot be controlled effectively by cultural (gardening) methods
- You are ok with eliminating beneficial insects and harmful insects
- You understand that once you start treating for a type of insect, you will probably have to continue treating.
(Side note—why do you have to continue treating? Insect populations naturally fluctuate. The population will naturally build up to a size that can no longer sustain itself and then will completely die off. For a time, you will have no damage. Then the population will steadily begin increasing again over time, as it repeats the cycle. If you treat for insects, you will not likely eradicate all of them, but run the risk of maintaining a fairly steady population. That means you will have continual limited damage, and not enjoy the period in the cycle without any insect problems at all.)
Are Natural Insecticides Safe?
Not necessarily. Natural insecticides are what the name suggests. They are made from naturally occurring compounds and chemicals, and are not synthesized in the lab. You still need to take precautions when you use natural insecticides, just as you would if you used synthetic insecticides. “The dose makes the poison,” is the mantra of nearly all pesticide training classes. Almost anything is poisonous if not handled properly or ingested or absorbed at a high rate.
What Are The Most Effective Natural Insecticides?
There are several insecticides that are made from naturally occurring compounds and have a terrific success rate for controlling pesky insects in the garden. Below is a list of these insecticides and some instructions for using them effectively. One note from a
wise old garden gnome
(I have learned a few things in my 179 years.) ALWAYS read the label on the natural insecticide you decide to use. My instructions in this article are meant to guide you to ask the right questions and find products that will work well for you. They are not meant to replace the legal labels on the products. “The Label is the Law.” That’s another thing I’ve picked up from landscapers wandering around my neighborhood. - Insecticidal Soap: This should be the organic gardener’s first line of defense for soft bodied insects like mites, whiteflies, aphids, thrips small scales and leafhoppers. Why? Because it is harmless to all but the insects.
Mix ½ cup (4 ounces) of it per gallon of water, or 2 tablespoons per quart, and put it in your garden sprayer. Spray it liberally on both sides of all foliage. You must actually drench the bugs for it to be effective. Once it dries, there is no residual effect. So, repeat as often as needed. You can buy actual isecticidal soap at your garden center, but I have great results using plain old liquid dishwashing detergent. Adding garlic or onion juice (liquefied in a blender) has some residual deterrent effect on many bugs. - Diatomaceous Earth: This is a great product that is made from ground up fossilized diatoms. Diatoms are tiny, single or multi-celled organisms that have cell walls made of silicon dioxide, or glass. Diatomaceous earth is basically a box full of ground up glass.
When you use it, you need to wear a simple surgical mask to keep from inhaling the tiny particles. Otherwise, diatomaceous earth is not harmful to humans or pets. Because of its sharp edges, if it gets into the lungs it is harmful. It kills soft-bodied insects such as slugs, and other soft-bodied insect larvae. It also gets into the joints of ants and other insects, causing them to bleed to death. - Neem Oil: Neem is relatively safe to humans and animals (and gnomes!) when applied properly. It is a natural compound that comes from the tropical plant Azadirachta indica.
Neem
controls aphids, caterpillars, beetles and many other pests by acting as a growth regulator. That means that insects that are exposed to the oil do not develop properly. It also keeps insects from feeding properly.
When applied according to the label, it is effective for about a week. You do need to wear protective gear because some studies have shown that neem can have affects on the reproductive systems of some animals when the animals are exposed to high doses. - Pyrethrum: This is one of the most widely used organic insecticides. It is derived from the flower Chrysanthemum cinerariaefolium, native to Africa and Australia. Pyrethrum can be organically grown, or synthesized in the lab, with similar results. You can find organic and synthetic versions of this insecticide in garden stores.
It works by disrupting the nervous system of the insect, and is used to eradicate whiteflies, mosquitos, aphids and other insects. Humans are not affected by the chemical, but because of its neurological activity, care should be exercised during use. (Listen to me, I sound like I’ve been sitting in a classroom for hours! I just want to make sure that I give gardeners the right information so that you can make informed decisions. There are a lot of misconceptions about natural insecticides!) - Rotenone: Rotenone kills insects by interfering with their respiratory functions. Insects generally die within a day or two of exposure to the chemical. It is naturally occurring, deriving from the plant Derris elliptica. It is very toxic to fish, and should never be used around water. My friends, the amphibians, are, as you might know, enduring major problems caused by insecticides and pesticides, and if rotenone is applied incorrectly, it can also do them damage. I would not recommend this one unless nothing else has worked.
The most important thing when deciding upon a natural insecticide is to think about those four questions above. Make sure you have reached the threshold where you definitely need to treat for insect problems. A few insect holes are better than any poison, even a natural one. Natural insecticides, though they still might harm the beneficial soil life, are still much safer for the environment and those that eat the produce. They dissipate quickly, leaving your fruits and veggies safe for your family. Still, use them only if necessary, and at the lowest effective dose, and follow the instructions on the label. Happy gardening, Geefrank
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