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Even if you’re new to crop farming, you’ve heard of pesticides.

Pesticides have a bad reputation outside of the agriculture community.

Between killing bees, causing cancer, and all of the other negative press, it’s no wonder why we’re shifting toward health-conscious and environmentally friendly organic foods.

But a lot of people, don’t really understand what pesticides are, or how they work.

That’s why we put together this HUGE guide.

In this article, you’ll learn about pesticide basics, how insecticides and herbicides work, how pesticides are dangerous, the safety of organic food, and safe methods of insect and weed control.

Use the table of contents, to skip to the parts that you’re most interested in.

Or read the whole article!

Remember, you can always save it for later too.

Now, let’s start learning about pesticides!


Pesticides 101

Types of Pesticides

When you think of pesticides, you probably immediately think of bug-killing chemicals.

But a pesticide, is any substance that’s used to kill, repel, or control plant, or animal life that are potentially damaging to agriculture.

This means pesticides can be made of anything and target any type of pest.

Pesticides are used in agriculture for two main reasons.

First, pesticides protect crops from being killed by pests.

Second, pesticides protect crops from diseases that are carried by pests.

As a result, farmers lose fewer crops.

That’s why higher yields are commonly attributed to pesticide use.

The two most common types of pesticides are insecticides and herbicides.

Insecticides repel and kill insects.

Herbicides control and kill weeds and other unwanted vegetation.

Other types of pesticides are:

Fungicides for mold and mildew

Algaecides for algae

Antimicrobials and disinfectants for germs and microbes

Rodenticides for rodents

Wood preservatives for protecting wood from fungus and insects.

Now that you know what pesticides are, it’s time to explore how they work.

To make it easier, we’ll only focus on insecticides and herbicides.



Insects are one of the most pervasive pests in agriculture.

These pests will destroy entire fields of crops if they’re not stopped in time.

Some insects eat your crops to death, while others spread deadly plant diseases.

But it’s important to note that not all insects are pests.

Bees, for example, are beneficial insects.

They play an essential role in crop cultivation: pollination.

Pollination is required for plants to produce fruits and seeds.

That’s why it’s important to identify the insects you see around your crops and be sure that they’re harmful before trying to get rid of them.

How Insecticides Work

Insecticides have a variety of forms and effects.

They can be sprays, dusts, gels, and baits.

And they have different levels of risk to other animals, the environment and people.

Insecticides also work in a bunch of different ways.

Some insecticides are made of chemicals that cause physical problems, like suffocation and dehydration.

Others are made from bacteria, mimicking ones found in insect-killing fungi or viruses.

Finally, some repel insects, rather than kill them.

Organophosphates, carbamates, and chlorinated hydrocarbons are examples of chemical insecticides.

They interfere with bugs’ nervous systems.

This leads to hyperactivity, random movements, tremors, convulsions, and paralysis.

Pyrethoids are insecticides that mimic natural chemicals to achieve similar results as the previous types.

They affect the potassium and sodium in an insect’s body, to interfere with the nervous system.

Pyrethoids mimic the effects of seeds of chrysanthemums, which can be used to naturally repel insects.

Insect growth regulators are an insecticide that targets young insects.

They trigger early molting or form changing, such as changing caterpillars into butterflies.

Because the change comes too early for its body to handle, the bug dies.

It’s also thought to be one of the safest chemical insecticides for humans and other animals, because we don’t undergo the same changes.

Finally, microbial insecticides are made from insect-attacking microorganisms.

The next pesticide we’ll look at, are herbicides.



Simply put, herbicides kill and prevent weeds.

A weed is any unwanted plant that may interfere with the growth of wanted plants.

Additionally, weeds produce seeds abundantly, have rapid population growth, spread easily, and survive long-term.

Some weeds can produce more than 100,000 seeds per plant!

Farmers don’t like weeds because they reduce crop yield.

Weeds kill crops, by stealing water, light, nutrients, space, and carbon dioxide from them.

That’s why herbicides are so popular.

Preventing weeds is usually easier than trying to fight them after they’ve appeared, but herbicides try to make fighting them easier.

How Herbicides Work

Like insecticides, herbicides come in a variety of forms.

They can be liquids, gels, powders, or pellets.

Some herbicides kill any plant that comes in contact with the chemical, these are called nonselective herbicides.

Others kill only weeds, without harming plants you want to keep, known as selective herbicides.

Most herbicides work better for specific types of plants, than others, making them less harmful to crops.

For example, plant growth regulators work mostly on annual and perennial broadleaf plants.

These herbicides make the affected weeds brittle, reduces photosynthesis, and affects the roots’ ability to intake nutrients.

Amino acid biosynthesis inhibitors affect a variety of different plants.

These interfere with enzymes and shut down metabolic activity in weeds, resulting in death.

Fatty acid, or lipid, biosynthesis inhibitors affect mostly grasses by killing the growth point.

Seed growth inhibitors cause abnormal cell development, killing weeds as seedlings.

And photosynthesis inhibitors block photosynthetic processes causing weeds to starve.

As you just learned, pesticides are ruthless killers when it comes weeds and insects.

But most farms use pesticides because they believe it’s the best way to prevent crop losses, from pests and diseases.

As a result, they see increased yields.

But many others believe, this advantage is outweighed by the dangers pesticides pose.

Pesticides are dangerous to humans, the environment, and wildlife.


Dangers of Pesticides

Dangers of Pesticides

Agricultural chemicals have been linked to many negative effects when it comes to humans, the environment and wildlife.

Humans are in danger from high exposure events and low doses found in food.

Pesticides damage ecosystems and natural plant growth in the environment.

And wildlife is often poisoned by chemicals that make it into their habitats from farms.

Some of these effects, are more harmful than others.

And some effects have long-lasting effects.


The long-term effects of pesticides in humans are rightfully feared.

Instances, where we are exposed to unusually high amounts of pesticides (high exposure events) are the riskiest for us.

For example, agricultural workers, who faced high exposure to pesticides were found to have lowered cognitive performance.

A 2011 study gave tests to agricultural workers to measure cognitive abilities.

The tests measured attention span, memory, verbal learning and more.

Workers with high exposure to pesticides, scored lower on the visual scanning and information processing tests, than workers who didn’t experience high exposure events.

Plus, high pesticide exposure events, have even been linked to loss of smell in agricultural workers decades later!

But it’s not only agricultural workers who face the dangers of pesticides.

Home gardeners who used pesticides rotenone and paraquat developed Parkinson’s disease 2.5 times more often than nonusers.

And pesticides are linked to cases of Alzheimer’s disease and dementia as well!

Some evidence shows that unborn children are at a higher risk when it comes to pesticide exposure.

Pregnant women who have traces of pesticides in their blood are more likely to have children with autism.

And organophosphate insecticides may damage an infant’s motor function before they’re even born!

Exposure to pesticides in the womb could cause motor function deficits, affecting abilities like grasping.

Some products, like herbicide “Roundup,” have even been linked to cancer!

When you consume pesticides, the toxins are stored in your colon, slowly poisoning your body.

You don’t have to work with pesticides to be affected.

We come in contact with pesticides by eating produce, breathing the air and drinking contaminated water.

The last two factors on that list, come as a result of the effects pesticides have on the environment.

And we can’t hope to avoid pesticides entirely, as long as they’re continued to be used recklessly and abundantly.


How pesticides are categorized, often depends on how long they stay present in the environment.

Some pesticides are “persistent,” lasting much longer than “non-persistent” chemicals.

But regardless of the category, their presence in the environment is concerning

What makes pesticides so dangerous to the environment, is the fact that most of them end up in areas that they weren’t intended for.

Pesticides contaminate our air, ground and water.

Between field run off, leaky storage tanks, improper disposal and aerial spraying, pesticides easily make their way to unintended places.

They even end up thousands of miles away from their origin!

At any given time, you will find pesticides in rain, groundwater, streams, rivers, lakes, and the ocean.

In fact, a series of studies by the US Geological Survey in the 1990s found that more than 90% of water from all streams contained at least one pesticide.

The same studies found pesticides in every major river with agricultural and urban connections and in 99% of urban streams.

With evaporation and subsequent rain, pesticides are found places where agriculture doesn’t even take place, such as deserted plateaus and polar zones.

Depending on the type of chemical, water contamination can last for days, weeks, months, or even years!

Plus, cleaning water is very costly and complex.

Sometimes, it’s even impossible!

If pesticides infect sources of drinking water, it puts us at even more risk than we already are.

When pesticides dissolve in water, it becomes toxic to humans and fish.

Some have properties that cause cancer or mutations.

Plus, when it’s in lakes, rivers and the ocean, all of the fish and other animals that live there may die.

In addition to water, pesticides damage soil.

When a pesticide contaminates soil, it destroys beneficial soil microorganisms.

If soil bacteria and fungi are killed, then the soil can’t hold onto nutrients very well.

This can limit the amount of nitrogen in the soil.

And nitrogen is essential to plant growth.

So, soil contaminated by pesticides could even damage the very plants it’s trying to protect!

This is especially true of nonselective herbicides because they aim to kill plant growth.

If these herbicides are used too much, the soil become inhabitable for plant life.

The effects pesticides have on the environment, can make it inhabitable for animals too.


Pesticides are detrimental to local wildlife populations as well.

Once eaten by animals, some pesticides transform in the liver, creating an even more toxic chemical.

For example, DDT insecticides aren’t naturally harmful to birds.

But once eaten, it turns into DDE, which disrupts calcium production and causes eggshells to be very thin.

Similarly, pesticides become more toxic as they move through the food chain.

This is called biomagnification, and it can even affect the children of top predators.

For example, if a worm is infected by an insecticide and a bird eats the worm, the bird will also be infected.

Speaking of birds, they may mistake pellet forms of pesticides for seeds.

This makes it even harder for birds to avoid consuming harmful chemicals.

Additionally, some pesticides kill food sources for wildlife.

For example, an herbicide may destroy foliage that local animals eat.

This may drive the animals away from the area, or even kill them through starvation.

Additionally, herbicides that end up in natural bodies of water may kill aquatic plants.

Without those plants, oxygen levels lower and fish suffocate.

Plus, extensive exposure to certain pesticides can make fish suffer physiological or behavioral changes.

These changes make them more vulnerable to diseases and predators, drastically reducing fish populations.

There’s even been cases of male tadpoles changing into females after herbicide exposure!

Even pyrethroids, which are considered safe for humans and other mammals, are extremely toxic for fish and aquatic insects.

Plus, some species, like bees and bats, are facing mass extinction due to pesticide use.

When pesticides kill bees or other beneficial insects, it lowers pollination and fruit production as a result.

This is another way pesticides harm the very crops they’re trying to protect.

With all of these dangers, it’s no surprise people are switching toward organic foods.


Organic vs Nonorganic

Organic food is often seen as a safer, healthier alternative to traditionally produced food.

But because organics can’t use the same convenient solutions, like cheap pesticides, to achieve higher yields, the food is often 3 to 5 times more expensive!

Plus, just because a vegetable is labelled organic, it doesn’t mean that pesticides weren’t used to make it.

In this section, you’ll learn the basics of organics and how organic food may be healthier but isn’t necessarily safer.

What is Organic Food?

Basically, “organic” means the food was produced without the use of synthetic chemicals.

To be certified organic by the US Department of Agriculture, farms have to produce and process their foods according to a set of federal guidelines.

These guidelines set standards for soil quality, animal raising practices, pest and weed control, the use of additives, and more.

So, while nonorganic food is made with chemicals, like pesticides and steroids, organic food has to be made in a natural way.

Organic produce can’t be grown in soil, that has had prohibited substances applied to it within three years.

The list of prohibited substances is long, but generally includes all synthetic fertilizers and pesticides.

Instead, organic farmers have to use natural substances and physical, mechanical, or biological farming methods, to achieve similar results.

If these natural methods aren’t working, an organic farmer can use certain approved synthetic chemicals and keep their organic label.

These synthetic chemicals are approved based on criteria that measure human and environmental dangers.

For meat farmers, animals have to be raised in living conditions that accommodate natural behaviors.

So, livestock have to be given access to pastures for grazing, fed only organic food and can’t be given hormones or antibiotics.

Additionally, genetically modified organisms (GMOs) can’t be used in organic food production.

What are the Benefits of Organic Food?

Fans of organic food will tell you it is healthier, safer, tastier, and environmentally safe.

A 2014 analysis published by the British Journal of Nutrition, showed that organic crops were less likely to contain pesticides.

The same study also found organic crops were almost 50% less likely to test positive for cadmium, a highly toxic metal that gets stored in the liver and kidneys.

And organic onions have been shown to have about 20% more antioxidants, than conventionally grown onions.

Additionally, a 2016 study showed organic meat and milk products have about 50% more omega-3 fatty acids, a type of healthy fat, than nonorganic products.

Organic milk, also has less saturated fat than nonorganic, according to the same study.

This means that switching to organic meat and dairy products, can raise omega-3 without increasing calories or saturated fat.

Plus, nonorganic livestock are given antibiotics.

The drug residue found in these meat products, are thought to make antibiotics less effective in our bodies.

But organically raised animals, aren’t given antibiotics, so their meat won’t affect our antibiotic resistance.

Additionally, the hormones given to nonorganically raised livestock, has been linked to increased risks of cancer in humans.

Eating organic mitigates these cancerous risks.

But pesticides don’t have much to do with meat production.

So, let’s go back to produce.

Despite some evidence showing organic produce being healthier, experts question the true nature of organic fruits and vegetables.

Is Organic Food Really Healthier?

The merits of organic food are often questioned.

Vulnerable groups, like pregnant women, children, elderly people, and sick people, may have the most benefits from eating organic foods.

But even head of the US’s national organic program won’t say if organic food is actually healthier or not.

The Mayo Clinic says, organic produce may have fewer traces of pesticides, but toxic chemicals are still found in them.

This could be because certified organic farms are allowed to use chemical pesticides too.

Or because pesticides pollute nearby air and water.

So even when you buy organic food, you might still be exposing yourself to pesticides.

And the reason organic onions have more antioxidants, might not be due to the lack of pesticide use.

The original study, published in 2017, says, “Differences [in antioxidants] were primarily due to different soil management practices used in organic agriculture rather than pesticide/herbicide application.”

Similarly, the reason organic produce has lower cadmium levels, is because of different fertilizer use, not pesticides, according to the study.

So while organic produce might have some health benefits, it’s not because it doesn’t have pesticides in it.

Between environmental exposure and organic food still containing pesticides, it might seem impossible to escape them!

But this doesn’t mean you should still use chemical pesticides in your garden, or farm.

Next, we’ll look at some ways you can control insects and weeds without the use of dangerous chemicals.


Safe Insect Control

Remember when we defined pesticides as “any substance” used to control pests?

That means that even natural and nontoxic insect controls are classified as insecticides.

But these methods of insect control are safer for humans, wildlife and the environment.

If you want to protect your crops from bugs without the use of synthetic chemicals, you have a lot of options!

In this section, you’ll learn about “do it yourself” (DIY) options, products to buy in stores, and strategies you can implement to fight off invaders.

Most of these safe solutions, work well for both indoor and outdoor growing.


Your first option is to make your own insecticides.

In addition to the ones you’ll find below, there are plenty of recommendations and recipes for DIY insecticide sprays.

No recipe is able to target all insects, and the sprays all affect insects in different ways.

So, it’s important to research the particular problem you’re having, in order to effectively solve it.

Oils and soaps are popularly used to craft DIY insecticides.

Certain essential oils have insect repelling properties.

For example, peppermint essential oil repels aphids, flies, spiders, and ants.

All you have to do, is add a few drops of essential oil to a spray bottle filled with water, shake it well and spray it around the base of your plants.

Alternatively, you can use insect-repelling vegetables, like garlic and hot peppers, to drive insects away.

Garlic and chili peppers have pungent scents that some bugs can’t stand.

Puree about half a cup of garlic, or spicy peppers with a cup of water. 

Strain out the pulp, then mix the liquid with a quart of water and a few drops of liquid soap.  

Spray where needed. 

You can also use vegetable oil and soap to kill some insects, instead of just repelling them.

Mix 1 cup of oil with a tablespoon of soap and keep it in a container, until you’re ready to use it.

When you’re ready, mix two tablespoons of the mixture with a quart of water.

Shake thoroughly and spray the infested plants.

This solution is most effective against aphids, mites, whitefly, and thrips.

You can also DIY traps for insects.

Paint a few small pieces of cardboard yellow.

Once the paint is dry, coat the cardboard in Vaseline, syrup, or something similarly thick and sticky.

Hang it, or prop it up, close to your plants to catch smaller insects.

You don’t have to make your own insecticides to solve the problem though.

Read on to find out how to safely protect your crops, using store-bought remedies.


You can easily find organic garden insecticides in stores.

But as we already know, the organic label can be tricky.

So, you may be worried about selecting something unsafe.

Luckily, the US Environmental Protection Agency, has a list of low-risk ingredients used in pesticides.

Compare the ingredients in your product, to the list, to make sure everything is safe to use.

You can find the list through the EPA website, or as a PDF here.

Another safe way to go, is neem oil concentrate.

Neem oil is a natural insecticide, made from the seeds of neem trees.

The oil kills insects by damaging their reproductive and biological systems.

Alternatively, you can also buy insecticidal soaps instead of making them yourself.

Premade ones will probably be more effective anyway, since they have been tested and controlled for quality.

Another option is diatomaceous earth.

Diatomaceous earth is a natural product made of crushed rock, that’s frequently used as a safe insecticide.

And it’s easy to find in garden stores too!

All you have to do, is sprinkle it on and around your plants, to prevent and kill arthropod insects.

The abrasive texture absorbs the waxy liquids arthropod, insects produce and dehydrates them to death.

You can also purchase premade sticky traps for your garden, instead of making them yourself.

Additionally, you may want to try implementing certain strategies to minimize the need for insect control products in the first place.

Other Strategies

Insect control strategies allow you to use other plants and insects against harmful pests.

One time-tested strategy is companion planting.

Companion planting consists of growing certain plants, in the same area, for their abilities to attract or repel certain insects.

For example, if you’re farming cucumbers, you may want to plant oregano, or marigold flowers, to repel mosquitos and whiteflies.

Companion planting can also be used to attract insects that prey on damaging ones.

For example, daisy flowers or mint plants attract wasps, which prey on aphids and caterpillars.

The only downside to companion planting to attract beneficial insects is, that it won’t work for indoor farms.

In which case, you could try introducing some beneficial insects by yourself.

For example, nematodes, a tiny worm-like insect, are commonly used for killing a variety of pesky insects.

You just need to be careful about the type of nematode you introduce to your garden.

Some nematodes are more effective against certain types of insects than others, while other nematodes may feed on your crops instead.

Additionally, if you’re growing crops indoors, keeping the room closed off and clean will reduce pest invasions.

Leaving garbage, food or decaying plant, matter inside your indoor garden, as it will attract a number of nasty insects.

Keeping things clean and tidy makes your plant room less attractive to invasive bugs.

These solutions will protect your crops from nasty pests, without keeping you up at night worrying about dangerous chemicals.

But we all know, insects aren’t the only pest.

Next, you’ll learn how to control weeds without using chemical herbicides.


Safe Weed Control

Safe weed control is actually a lot harder than safe insect control.

That’s because it’s hard to make products that differentiate between wanted plants and unwanted plants.

At the end of the day, weeds are made from the same stuff your crops are.

One of the advantages to growing indoors, is that weeds don’t occur.

Since you’re growing in a controlled environment, weeds can’t get inside and take root.

But for outdoor growers, weeds are a frequent and common occurrence.

When it comes to safe weed control, it’s important to consider the lasting effects many products can have on soil and nearby plants.

Both DIY and commercial products can damage soil fertility and other plants.

When implementing weed control, be sure to research your product thoroughly and use it as carefully as possible.


It’s important to know that DIY weed control works best as a short-term solution.

The most basic, and probably safest, herbicide you can use in your garden is boiling water.

It’s just water, so there’s really no risk of introducing toxic elements into the environment.

All you do, is boil water and pour it on the unwanted weeds.

This is best for weeds that haven’t made it into your garden yet, because boiling water will kill your crops too.

But it won’t kill the roots, so there is a risk of reoccurrence.

You can also make your own herbicide spray using salt.

Use a small ratio of 1-part salt to 8-parts water to start.

Add a bit of dish soap to make the consistency stick to leaves better.

Put the mixture in a spray bottle and spray the weeds directly on the leaves.

Do not get any of the spray on your crops.

Be careful to get as little on the soil as possible, as too much salt damages soil.

If you need more potency, increase the ratio of salt to water, to as high as 1-part salt to 3-parts water.

Vinegar and dish soap will also kill weeds.

You don’t need to dilute the vinegar at all.

In fact, the higher the concentration, the more potent it will be.

Keep in mind that stronger concentrations of vinegar pose a danger to humans, so don’t let it come in contact with your skin.

Vinegar won’t damage the soil, but it will damage any plants it comes in contact with.

So be sure to only apply it to the unwanted weeds.

If you need something that works better in the long run, you should turn to purchasing an organic herbicide.


Commercial organic herbicides work better as long-term solutions, than DIY herbicides.

These store-bought products were designed with environmental, human and animal safety in mind.

This means they’ve been made to break down over time, leading to shorter effects on the surrounding environment.

Like with store-bought insecticides, you should compare the ingredients to the US Environmental Protection Agency’s low-risk pesticide ingredients list.

You can find the list through the EPA website or as a PDF here.

Additionally, look for plant-derived ingredients like clove oil, citric acid, and acetic acid.

Unfortunately, only nonselective organic herbicides are available.

Nonselective herbicides kill all plants—wanted or unwanted.

Hopefully, as research continues, selective organic herbicides will be developed.

For now, it’s too difficult to develop herbicides that can target weeds, while keeping other plants alive, without the use of synthetic chemicals.

If using nonselective products to kill weeds sounds too risky, there are even safer approaches you can take.


Most strategies for weed control, that don’t include using herbicides, involve preventing weeds before they grow.

To do so, you need some type of ground cover.

One type of ground cover uses black plastic sheets.

These prevent sunlight from reaching the soil.

As a result, weed seeds can’t germinate and grow.

To use a ground cover sheet, moisten the soil and remove any unwanted plants, dead foliage and debris.

Then, cover the entire growing area with strips of black plastic sheeting.

Cut holes or leave spaces for plants you want to keep alive.

Then, cover the sheet with organic mulch and smooth it into an even layer.

This makes it look more natural, adds weight to the sheets and gives you extra protection from weeds.

Alternatively, you can go a more natural route and use other plants to cover the ground.

Ground cover plants grow so thickly that sunlight doesn’t reach the soil, preventing weeds from growing.

Like with any plant, research the best crop to fit your growing situation.

Plus, cover crops help add nutrients back into the soil.

If all else fails, you’ll have to just remove the weeds by hand.

It can be a lot of work, depending on the size of your garden.

But it’s very effective.

Unlike other methods, it kills weeds by the root, ensuring the same plant won’t regrow.

Plus, it has the benefit of creating holes in your garden.

These holes aerate your soil, helping your other plants grow!


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