How you apply organic pesticides is as important as what you apply. People often make the mistake of assuming that organic pesticides are safe for pollinators and good bugs because they are safer for humans. That is not necessarily so—in fact, in most cases, it is not.
Organic pesticides and herbicides may still harm beneficial insects. Most of these products do not know how to differentiate between harmful and beneficial insects—their anatomy and function are too similar (though some organic pesticides are species-specific and so target a limited range of pests).
This does not mean that we can’t safely use the organic solutions that we deem safer for us. It simply means we need to be educated when we do. No matter what kind of pesticide we use to solve a problem in our gardens, we must know how to do it without causing harm, or at the very least, causing the least amount of harm possible to the insects that we do need.
- What Differentiates Organic from Conventional Pesticides
- Tips for Using Organic Pesticides Safely
- Follow label instructions
- Identify invaders
- Apply targeted interventions
- Get familiar with pest life cycles
- Reapply as recommended
- Use broad-spectrum products responsibly if you are targeting several insect pests
- Apply when good bugs are in bed
- Avoid applying to plants in bloom
- Avoid spraying in windy conditions
- When appropriate, use dual- and multi-purpose products
- Target the plant-eaters
- Accept some bad bug presence
- Use only when needed
- Organic Doesn’t Automatically Equal Harmless
- Protect Yourself, Too
What Differentiates Organic from Conventional Pesticides
Virginia State University describes organic pesticides as “generally considered to be pesticides derived from naturally occurring sources such as minerals, plants, or animals. These chemicals are broken down relatively quickly by weather or soil microbes.”
As they explain it, a characteristic of organic pesticides is that they come from natural sources. They are not synthesized by a chemical process, and they are not chemically changed when they are produced into their usable forms. This is a general definition, and it should be noted that there are some synthetically produced products that are approved for organic use, such as copper sulfate and peracetic acid (an organic peroxide), that are approved for organic production in the U.S.
Tips for Using Organic Pesticides Safely
The good news is that organic pesticides can effectively control damaging insects with a minimum of harm when used as they are intended and when care is taken to avoid exposure to beneficial insects and pollinators.
Being aware that there is a risk is the first step. Now that you have it, know how to capitalize on it. There are a number of steps you can take to protect pollinators and beneficial insects while using organic pesticides:
Follow label instructions
This is the most critical piece of advice you can follow. Pesticide labels are carefully constructed to give you the information you need to apply them as safely as they can be. This includes mixing and concentration instructions, types of insects targeted, beneficial insects that can be collaterally harmed, and information about how and when to apply products to protect both your plants and their friends (and also you!).
It is especially important to follow mixing and dosing instructions because even a product that is safe at proper concentrations can become harmful if it is prepared too strongly.
There are two reasons to get to know the insect invaders that are in your garden. The first is to make sure you have properly identified the insect and that it is, in fact, a harmful insect. Some bad insects can look a lot like beneficial insects, and vice versa. You wouldn’t want to mistakenly declare war on a helpful bug and contribute to its decline. Be aware that the difference between some good and bad bugs can be very subtle, so take pains to make the right identification.
When identifying, it is important to also identify the larval stages of insects. Many beneficial bugs, like ladybugs, look quite nefarious as young larval ladybugs. Ladybug larvae look almost alligator-like, and at first glance, you would assume something that looks like that would have to be bad. The opposite is true, though, because these little orange and black alligators feed on other insects and the eggs of other insects.
The second reason you want to know what insects you are dealing with is so that you know what product to use. Not all organic pesticides are broad spectrum (in fact, not all conventional pesticides are broad spectrum, either). If you apply an insecticide without knowing what you are trying to kill or what it takes to kill it, you can be putting beneficial insects at risk and not killing any of the damaging insects at all.
Apply targeted interventions
Some organic pesticides are very well targeted to only kill specific types of pests. The more targeted the product, the less likely it is to accidentally kill something good.
One of the more common organic products that target specific types of pests is Bacillus Thuringiensis (Bt). Bt is a highly specific pesticide, but it only targets specific pests. There are also different strains of Bt that target specific species. Know which strain will work on the specific insect you are having a problem with and use that. This will narrow down the target even more and impact fewer types of beneficial insects.
In general, Bt only works on worm- and caterpillar-type pests and the larvae of several garden pests and beetles. It is very effective at the larval (worm or caterpillar) stage, but once those pests turn into plant-eating adult beetles or moths, you will need to use a different product. Still, the larvae themselves (like cabbageworms) are often the ones causing the most damage and are often the stage of insect you need to control immediately to protect your crop. And controlling the worms that become the moths will stop them from multiplying, which will keep populations and pressure under control.
Get familiar with pest life cycles
It also helps to familiarize yourself with the life cycles of damaging garden insects. This is important so that you know which points in the life cycle certain pesticide products are effective. That way, you are not spraying a product that creates a degree of risk to beneficial insects for no reason.
Neem oil, for example, may only work on some insects at certain stages of life; for some insects, it may work at a soft-bodied larval stage but not in a hard-bodied adult stage, or its effectiveness may be less on adults (this can be different for different types of insects, too). Similarly, Bt may work on a larval or worm/caterpillar stage but will not work on adult beetles or moths; it is exclusively effective on caterpillars and worms.
Reapply as recommended
It is common for pesticides, especially organic pesticides, to be reapplied in one- or two-week intervals after the first application. This is usually to control any new hatches from eggs that were laid before the first round of adults were killed. Some products can neutralize insect eggs, but not all do.
Once you have taken the step of using an organic insecticide, you should follow through to complete the task. Though this may seem excessive, and it is true that the less product we use of any kind, the better, it makes the most sense in the long run to complete treatment than to keep starting and stopping when insect populations reemerge in greater numbers.
Use broad-spectrum products responsibly if you are targeting several insect pests
A broad-spectrum product may sound like a nuclear option that is doing more harm than good, but if you have several types of insects that are causing big problems in your garden, it’s better to apply one product responsibly than to apply several different products in several different applications.
Every time you apply a pesticide, you create a risk to beneficial insects, so the fewer types and times you apply a product, the better it is for everyone. The key, again, is to know if what you are applying can manage your needs and to use pesticides as directed, conscientiously.
Apply when good bugs are in bed
One of the best ways to protect pollinators and beneficial insects is to apply them at times of the day, night, or season when they are not present. This can be difficult if the insects you are trying to protect make their homes in the plants you are spraying, but many of the insects and pollinators we are aiming to protect are those that live “off-site” in nests, hives, or larger trees and bushes. While bad bugs will tend to stay on their host plants, pollinators that are there to pick up groceries only come when they need to. They may be nearby, but they may commute to your plants during the day when they feed or collect from the plants.
For example, most butterflies are active during the day and hide and rest at night in rocks, under leaves in trees, or in the grass. Honeybees and solitary bees go back to their hives (though some males do not). Hummingbirds go back to their nests in trees. If you go out to your garden and spray before they come out or after they go home, and you choose your product carefully, you can do a lot to protect them.
Of course, you may need to do a little research to know where your good bugs bed down at night to know when they are most likely to be present and active. You will also need to observe your garden and get a feel for the times of day when the good guys come out and when they pack it in for the night. You may have to commit to waking up a little earlier or staying out a bit later in order to work opposite them—but the little loss of sleep for that day or two is definitely worth it.
Avoid applying to plants in bloom
Pollinators are most likely to be present when plants are in bloom. They come for the goods they need, and it is the blossoms, pollen, and scent of the flowers that attract them. If you can, focus your insect controls on times when your plants are not blooming. You’re not likely to have bees and pollinators on your plants then, anyway.
If you cannot wait until your plants are not blossoming, apply when pollinators aren’t present and at least avoid applying products to plant blossoms. If possible, create a landing buffer around the flowers to reduce the likelihood of insects coming into contact with residue or powders that may harm them.
Avoid spraying in windy conditions
Apply organic pesticides when conditions are very calm. Even a good breeze can cause pesticides to drift. This is especially true of sprays, but it is also true of light powders and diatomaceous earth. You’re taking great pains to make sure you only apply your pesticides where they are needed, so take pains to make sure they only go where you want them.
When appropriate, use dual- and multi-purpose products
Some of the products that we use as insect control are also good for other things, like controlling plant diseases -- especially molds, mildews, and diseases caused by fungi. Just as there are broad-spectrum insecticides, there are products that are multi-purpose, too.
For example, Neem oil, one of the leading organic pesticides, is also a natural anti-fungal product that can help control diseases like powdery mildew. Diseases like powdery mildew are often (but not always) spread by insects. So, for example, if you have a problem with aphids and powdery mildew, use Neem oil, which can control them both. This will reduce the need for applying a second product that might also be risky for pollinators and beneficial insects. Plus, it cuts down on your workload.
Target the plant-eaters
If possible, use products that stop plant-eaters, not the insects that eat plant-eaters. There are products that are designed to work only when wet or when ingested but that have limited effects on birds and insects that eat those insects. Spinosad is one example. It dries on the plant and has residual effects that kill chewing insects when they eat the leaves and stems that have dried Spinosad on them. Do also be aware, though, that the product, when wet, is harmful to bees (but reportedly is not harmful after it has dried)
Accept some bad bug presence
You don’t want pests to get out of control to the point that the quality or safety of your produce suffers or to the point where plants are not able to flower or produce at all. But strong, healthy plants can withstand some insect pressure; they are designed to be by nature. Adjust your thinking. If your plants are overcoming the populations, focus, perhaps, on control, rather than eradication.
Some gardeners even choose to overplant to account for insect damage. They plant more plants than they need for their own use, and then they don’t worry as much if they lose some of their harvest to insects. (Admittedly, there is a risk in doing this, and no action may still leave you with a lot of insect-riddled plants and no produce, but it’s an option and a risk worth considering.)
Use only when needed
A pesticide is still a pesticide, and there is no such thing as a 100% safe intervention. Using pesticides as little as possible and working with the good guys in nature will reduce the risk in your yard and garden. Often the best approach is to use pesticides as part of an integrated approach, like working with parasitic wasps and beneficial insects, removing damaging insects by hand when reasonable, using floating rows covers, or encouraging birds.
Still, there may come a time—and it often does—when you need more help, and an organic pesticide becomes necessary. You may even have imported pests in your garden that do not have natural predators because they are not natural food sources for your local beneficial predators.
This does not mean, however, that we should apply organic pesticides more than we need to. This will only increase the risk to beneficial insects and reduce the biodiversity that helps us keep pests in check.
Organic Doesn’t Automatically Equal Harmless
Not to insects, anyway. Organic pesticides are chosen and targeted more to be safer for human consumption. They are intended to reduce the chemical pesticides, poisons, and toxins that we consume when we eat the produce. And they are chosen because they break down through natural processes more quickly and leave less of a trace behind (through sun, rain, and decomposition, for example).
This does not mean that organic pesticides are harmless, though. They may be mostly harmless to us, but they are not harmless to many of the insects and pollinators that we need to protect.
Protect Yourself, Too
A final note of precaution: As with many things we come across in life, organic pesticides can still be harmful to humans, especially in high concentrations and at the time of application. This is not true of all organic pesticides, but the risk is there. The point is, it’s important to be aware of what you’re using and how you’re using it, and what risk there is to you. Read your product labels completely, and if precautions are advised, take them.
Precautions may include things like covering your eyes, your skin to prevent burns or to wear a mask to stop you from breathing in too much of the product. Because sometimes too much of a good thing can be a bad thing, even if that thing is something that is safe in other forms or at other levels, it’s still smart to be safe. After all, this is the exact reason you are choosing to use organic pesticides, to begin with!