Organic produce at the grocery store might be pricey, but organic gardening can save you money. Most novice home gardeners quickly discover that growing food has its challenges. Wherever you plant juicy, succulent vegetables, insects flock to feast before you’re even close to harvest time! Controlling garden pests in an organic garden can be frustrating and confusing. How are you supposed to manage an insect infestation without pesticides? The answer is simple: organic pesticides.
The term “organic pesticide” may sound like a contradiction. But there are plenty of non-toxic treatments for garden pests, including many you can make yourself. Understanding the differences between the various organic pesticides will help you figure out the right treatment for your garden. Here are the basics you need to know about organic pesticides.
Organic Vs. Synthetic Pesticides
Yet another reason to grow your own food at home: Large-scale organic farmers have a dirty secret… they use lots of pesticides. What’s worse? These pesticides show up in the organic produce people take home and eat! There are over 20 chemicals approved for use on organic farms. The U.S. Department of Agriculture approves these pesticides because they’re naturally derived instead of synthetic. So what’s the difference?
They’re all used to kill insects. But natural pesticides are based on mineral dust, plant extracts, and oils. Synthetics are manufactured chemically and are sometimes makeshift versions of a natural pesticide (pyrethrum and permethrin, for example). Synthetics last longer and are cheaper, but more dangerous. Organics are safer but less effective, so you may need to apply them more often or in larger amounts to do the trick.
For a small-scale home gardener, reapplying a natural pesticide a few times is no big deal. On an industrial-scale organic farm, the volume of natural pesticides repeatedly applied to crops can be excessive. This may even do more environmental harm than the smaller amount of synthetics applied to conventional crops!
Over the Counter Organic Pesticides
There are countless organic pesticides to choose from, but the following are the most common.
Bt (Bacillus thuringiensis)
Bt is a biological pesticide, meaning it’s made of a living organism. This bacteria is toxic to some insects, such as caterpillars. It’s excellent for controlling beetles, moths, flies, and mosquitoes. This pesticide comes in a concentrated form that you mix with water and spray onto plants. Scientists consider it one of the safest pesticides around. Use it in ponds or fountains to kill mosquito larvae as it has no effect on fish, amphibians, and birds who ingest it.
Derived from a daisy, pyrethrins are organic compounds that are toxic to insects. Do not confuse these with pyrethroids or permethrin– the much more toxic synthetic version of the natural compound. This organic pesticide is best for use on infested plants, not all over the garden. It is toxic to all insects, including pollinators and beneficial insects, as well as fish and amphibians, so use sparingly and with caution.
Used for hundreds of years as a natural pesticide, neem oil is extracted from the seeds of a neem tree. Because the compounds are only toxic to insects when eaten, it’s safe for pollinators and most beneficial insects. It breaks down rapidly in the sun, adding to its low level of risk for humans.
Neem oil helps get rid of aphids, mealybugs, scale, and whiteflies. It’s also an effective antifungal and helps prevent powdery mildew, rusts, root rot, black spot, and sooty mold. It’s best to test neem oil on a leaf before treating an entire plant because some plants may have a bad reaction.
There are a plethora of insecticidal soaps on the market, but all are essentially the same: potassium salts of fatty acids. These products work best to control aphids, mealybugs, thrips, scale crawlers, and spider mites.
These sprays are safe and non-toxic, but they are also expensive for what they are. You can save money by making your own.
MYO Organic Pesticides
If you want to go fully organic, making your own natural pesticides is the way to go. Here are a few of the most reliable, completely non-toxic recipes home gardeners swear by.
Homemade Insecticidal Soap Spray
For mere pennies, you can make your own insecticidal soap with ingredients you already have in the kitchen! Inside a clean spray bottle, mix two teaspoons of gentle liquid soap with one quart of water. Shake well, and spray directly on infested plant surfaces. Apply early in the morning or early in the evening and make sure you get the tops and bottoms of leaves.
Neem Oil Insecticide
Spray-on neem products are often expensive and contain other ingredients. With a bottle of pure neem oil, you can make a DIY spray-on insecticide that costs a fraction of store-bought. Add two teaspoons of neem oil and one teaspoon of mild soap to one quart of water, mix, and spray on the leaves of an affected plant. This is a very useful treatment for scale, and can also work as a preventative insecticide on healthy plants.
Garlic Insecticide Spray
Forget vampires. What garlic excels at repelling is insects! Rich in sulfur compounds, garlic deters aphids, bean beetles, cabbage worms, potato beetles, spider mites, slugs, and snails.
Make a basic spray by pureeing two whole bulbs of garlic and a little water. Add a quart of water to the blender and let it sit overnight. Strain the stinky mixture through a sieve, add a couple of teaspoons of oil and one teaspoon of liquid soap and mix well. Store the jar in the refrigerator. To use, add one cup of the mixture to a quart of water and spray on the leaves of infested plants.
A traditional insecticide, tobacco water has protected crops for hundreds of years. Nicotine is the active ingredient, but unlike the toxic neonicotinoids that kill pollinators, tobacco water is only effective against insects that munch plant leaves.
To make this organic insecticide, steep one cup of loose-leaf tobacco in a gallon of water. Let it sit overnight, then strain and use the “tea” to spray garden plants.
Particularly effective against caterpillars, aphids, and flea beetles, most insects won’t eat leaves sprayed with tobacco water.
There are many ways to protect your garden from insects without poisoning the planet or your family! And you don’t even have to use spray-on products. You can order predator insects like ladybugs or praying mantises to help gobble up insects, too. The bottom line? You can save your money, save your garden, and save the earth by using organic pesticides.