When gardeners think of organic pesticides, they usually think of peppermint oils or other homemade concoctions. While these homemade insect repellents have their place, these are far from the only USDA-approved organic pesticides.
Below you’ll find an overview of 26 of the most popular USDA-approved organic pesticides used by home gardeners and commercial growers worldwide. These biopesticides are used to treat a wide range of plants for insects and fungus with minimum negative impact to the plants and the surrounding environment.
Bacillus subtilis
Bacillus subtilis is more commonly known as hay bacillus or grass bacillus. Bacillus subtilis is a microorganism introduced as a soil additive to out-compete more harmful bacteria in the soil. These sturdy and aggressive bacteria attack other bacteria strains by producing antibiotics and growth inhibitors.
Here are the major advantages of using Bacillus subtilis:
- Acts as a biopesticide against plant-damaging bacteria
- Increases the solubility of phosphorus in the soil, reducing the need for phosphorus-heavy fertilizers
- Triggers and increases the natural resistance of plants to pests through systemic acquired resistance, where plants have their defenses up before an infestation occurs
The relatively low cost makes Bacillus subtilis an affordable way to reduce plant pathogens and enrich the soil at the same time.
Bacillus Thuringiensis
Bacillus thuringiensis is in the same family as Bacillus subtilis, and is similarly used as a microbe to out-compete more harmful soilborne pathogens in the garden. Bacillus thuringiensis is commonly known as BT. The benefit of using Bacillus thuringiensis is that it naturally produces proteins that are fatal to various insect larvae.
The insects targeted by Bacillus thuringiensis include some of the following:
- Caterpillars
- Black flies
- Cabbage moths
- Beetles
- Mosquitoes
Bacillus thuringiensis is used in topical applications as an organic pesticide. There are also several industrial food crops such as soybeans and corn that have been genetically altered to produce these bacteria naturally.
Bueaveria bassiana
Another type of microbe used as a biological agent is Bueaveria bassiana. This soilborne fungus is naturally occurring in topsoil found worldwide. In arthropod insects, this microbe inflicts white muscardine disease. Beauveria bassiana was the first insect pathogen identified in the 1800s.
Beauveria bassiana is used to control the following insect types:
- Termites
- Thrips
- Bed bugs
- Whiteflies
- Beetles
- Aphids
Coniothyrium minitans
Coniothyrium minitans is a microbe used to control white mold. White mold is a devastating soilborne pathogen that can cause the following crops to fail:
- Soybeans
- Dry beans
- Lettuce
- Carrots
A major advantage of Coniothyrium minitans is that they can be applied at several different points during the growing process: before planting, at planting, during cultivation, or after harvest. Coniothyrium minitans is a biological fungicide that is typically only used in commercial agriculture systems.
Corn Gluten
Corn gluten is a useful organic pesticide because it kills insects and performs non-harmful weed control. It’s safe for the environment and isn’t toxic to either humans or other animals. Many insects such as slugs and ants will attempt to ingest cornmeal only to be killed by it since it is indigestible to them.
Cornmeal also has the advantage of being easy to source since it is commonly used in baking products and many people keep it around the house. This convenience makes it a practical choice for organic home gardeners.
Cydia pomonella granulosis
Cydia pomonella granulosis is an insect virus formulated into a biological pesticide under the brand name CYD-X through Certis Biologicals. Cydia pomonella granulosis has been specifically designed to attack the larvae of codling moths.
This biopesticide is host-specific in that it only attacks codling moths and nothing else. This makes Cydia pomonella granulosis very safe to use as an organic pesticide since it doesn’t negatively affect pollinators and other beneficial insects. It’s also non-toxic for human and animal ingestion.
Diatomaceous Earth
Diatomaceous earth is a popular soil additive used in home organic gardens because it is effective against a wide variety of pests. On a microscopic level, Diatomaceous earth is covered with tiny barbs that puncture an insect’s body and draws the fluid out of it to kill it.
Diatomaceous earth is effective against these insects:
- Bedbugs
- Darkling beetles
- Silverfish
- Black and red ants
Another reason Diatomaceous earth is popular with home gardeners is that it is relatively inexpensive compared to some biological pesticides.
There are two big drawbacks to Diatomaceous earth. One is that it is not host-specific, which means it can just as easily damage and kill beneficial insects as it can pests. Because of this tendency, Diatomaceous earth should be used sparingly. Diatomaceous earth can also be irritating to the respiratory system for both humans and poultry, so wear a filtered mask during application for safety.
Horticultural Vinegar
Although many people may associate horticultural vinegar with weed control, it is an acidic solution that is also effective in repelling garden pests. Here are some of the pests that can be controlled using horticultural vinegar:
- Slugs
- Moths
- Ants
- Mosquitoes
- Fruit flies
Horticultural vinegar’s ability to combat both insects and weeds makes it a useful tool in any home gardener’s arsenal.
Hydrogen Peroxide
Hydrogen peroxide is unique among organic pesticides for its use against rootworms and other soilborne pathogens. Most traditional topical pesticides are unable to prevent such pests.
Hydrogen peroxide solutions are popular in eliminating the following pests:
- Fungus
- Gnat larvae
- Cutworms
- Parasitic nematodes
- Insect eggs and larvae buried in the soil
Hydrogen peroxide is beneficial because not only does it act as an effective organic pest control, but it can also be used to improve root aeration and prevent root rot. Additional hydrogen peroxide uses in the garden include the following:
- Algaecide: Along with acting as an organic pesticide, hydrogen peroxide can also remove unsightly algae from garden ponds and reflecting pools.
- Prophylactic seed treatment: Before planting, seeds can be treated with a preventative dose of hydrogen peroxide to prevent the seedlings from succumbing to soilborne fungal infections after germination.
- Infection preventative for damaged plants: For trees that have suffered damage or plants in the garden that have exposed broken branches, a topical dose of hydrogen peroxide can prevent the onset of fungal or bacterial infections in the plant’s open wound.
Hydrogen peroxide can be cheaply obtained at any corner drugstore, making it one of the most useful tools for a home organic gardener when it comes to defending the garden.
Lime Sulfur
Lime sulfur is a popular organic insecticide used to protect fruit in the early spring, especially small cane and bush fruits such as blueberries, raspberries, and blackberries. However, lime sulfur sprays are also used on stone tree fruits and grapes.
As a biological pesticide, lime sulfur can control the following diseases in plants:
- Phomopsis
- Anthracnose
- Spur blight
- Cane blight
- Black rot
- Powdery mildew
While lime sulfur is popularly used in large-scale orchard operations, it can also be adapted for home use on fruit trees, grape trellises, and berry patches. Lime sulfur is an especially effective pesticide in warm and moist climates where fungal infections of plants are common.
Elemental Sulfur
As an organic pesticide, elemental sulfur is an effective killer of fungi. While elemental sulfate drift can damage some sulfur-sensitive plants near areas where this fungicide is used, it’s generally considered to have a low impact on surrounding wildlife and plants.
Elemental sulfur is also considered a broad-spectrum fungicide, which means it is used effectively against many different varieties of fungi and plant pathogens. This insecticide is available in several application types: dust, wettable powder, and ready-to-use sprays.
In addition to its use as a fungicide and an insecticide, elemental sulfur can also be used in the following applications:
- Acaricide
- Rodenticide
- Insect repellent
- Fertilizer
- Soil amendment (used to lower soil pH)
Elemental sulfur has a slightly unpleasant smell when applied, but it is approved as safe around livestock, people, and pets. This makes it a practical soil additive to help prevent the spread of both insects and fungal diseases.
Sodium Bicarbonate
Sodium Bicarbonate is a fancy word for common household baking soda. Sodium bicarbonate is successfully used to treat several different garden pests and diseases, including the following:
- Cabbage worms
- Powdery mildew
- Aphids
As well as acting as a pesticide, sodium bicarbonate offers other advantages to plants as a fertilizer. It can also sweeten and improve the flavor of garden tomatoes. This makes it a useful addition to any vegetable gardener’s toolkit.
Mixed with canola oil, water, and detergent dish soap, sodium bicarbonate is used as the basis for an effective homemade insecticide.
Here are a few additional uses of baking soda in the garden:
- Fungicide for black spot disease in roses: By mixing four teaspoons of baking soda with a gallon of water, you can create an effective fungicide that is used to treat roses for black spot. This solution can also be used to prevent powdery mildew on squash and other field crops.
- Garden cleaner: Baking soda is useful for cleaning all kinds of things in the garden, from garden tools and pots to birdbaths and patio furniture. Because it is a mild abrasive agent, it is used to scrub objects clean without scratching their surfaces.
- Weed herbicide: Full-strength baking soda can be dumped on top of a weed and then sprinkled with water to activate the baking soda and kill the plant. Be aware that baking soda will kill grass just as easily as weeds, so be careful in its application to avoid brown spots on the lawn.
Kaolin Clay
Kaolin clay (also known as China clay) is a popular organic additive with several applications in the garden. It’s also an effective pesticide that is harmless for human consumption, making it a suitable choice for protecting food crops.
Here are some of the ways kaolin clay is used in the garden:
- Insecticide
- Bird repellent
- Protection against sunburn/heat stress
Kaolin clay works by forming a powdery clay barrier on plant leaves and fruit after the clay solution has been spread over the plant. This harmless clay can be washed off before any fruit on the plant is eaten. It acts as a serious deterrent to any pests such as cucumber and flea beetles.
Along with providing protective properties to plants and fruits, kaolin clay has also been shown to improve fruit coloring. Since the clay protects the flesh of the fruit from the sun, it can help prevent spots of sun scald or uneven ripening.
Myrothecium verrucaria
Myrothecium verrucaria is one of the most effective biopesticides to use against parasitic nematodes. A major benefit of this bacteria as an organic pesticide is that while it is great at killing parasitic nematodes, it leaves free-living nematodes unharmed. This means that Myrothecium verrucaria is minimally damaging to soil ecosystems and microorganisms.
Because this bacteria is designed to attack soilborne pathogens, it is can be incorporated into the soil at the base of plants in the first three to six inches of topsoil. This bacteria is used as a biopesticide for all types of field crops and trees.
Myrothecium verrucaria is an effective organic pesticide for food crops since it leaves the fruits of the plant unaffected.
Non-Detergent Insecticidal Soaps
Non-detergent insecticidal soaps are among the safest pesticides used in organic gardening, which makes them a great option for home garden applications. These soaps can easily kill a wide variety of insects through suffocation. The waxy film created by the soap coats the insect’s body and prevents it from being able to breathe through its skin.
Insecticidal soaps are used to eradicate the following insect types:
- Mealybugs
- Aphids
- Thrips
- Scale mites
- Spider mites
Non-detergent insecticidal soaps are similar to the homemade insecticides that are made with household dish soap. The advantage of using insecticidal soaps versus dish soap is that many household detergents contain harsh caustic chemicals that can damage plants.
Luckily, insecticidal soap is a great tool for gardeners on a budget. Insecticidal soaps should be re-applied often since they will eventually be washed away by rain or sprinkler irrigation.
Pheromones and Pheromone Traps
Pheromone traps lure insects via chemical signals. In swarming insects such as beetles, pheromones are used to show other beetles where to congregate. In insects with more complicated hierarchies such as ants and bees, pheromones are also used to mark pathways.
Insect traps that use species-specific pheromones are useful in organic gardening applications since they can help control insects without introducing dangerous chemicals into the environment that may harm beneficial insects.
In organic gardening, these traps typically use pheromones associated with the female insect of whichever species is being targeted. This draws in male insects to be killed by the trap and can reduce the number of insects that breed in the garden over the growing season by reducing the number of potential mates for the females that are left.
Popular pheromone trap styles include the following designs:
- Bottle traps
- Delta traps
- Water-pan traps
- Funnel traps
Neem Oil
Neem oil is a seed oil collected from the neem tree and is used in hundreds of pesticides. Neem oil is used on a range of different food and ornamental plants but is especially popular for the control of black spot disease in roses. The active ingredient in neem oil that works as a pesticide and fungicide is Azadirachtin.
Neem oil affects insects in the following ways:
- It disrupts insect feeding
- It acts as an insect repellent
- It interferes with insect growth and reproduction
Even though neem oil is effective against insects, it doesn’t create the same “death zone” around plants that can kill beneficial pollinators and predator insects in the garden environment. Instead, neem oil only targets leaf-eating insects.
Neem oil is commonly available in most gardening supply stores in a spray form. This oil is a good preventative fungicide but must be applied several times throughout the growing season to stay effective.
Caraway Oil
Caraway oil is an aromatic oil that has an extremely high repellent efficacy in lab studies at 96.7 percent. As a common essential oil, caraway oil can be mixed into a solution with other strong aromatic oils such as grapefruit oil and clary sage to help repel pests.
Fennel Seed Oil
Like caraway oil, fennel seed oil is another aromatic oil that works well as an organic pest repellent. Fennel seed oil works by acting as a strong irritant to insects and their respiratory systems. It can be combined with caraway oil or other aromatic oils such as peppermint to increase their repellent properties.
Quassia Armara
Quassia armara is also known as paradise tree, amargo, or bitter-ash. The chipped wood from this tree acts as a natural insecticide that has no harmful effects on plants or animals. The wood chips are used as mulch around plantings where they can kill any leaf-eating insects that try to eat them. The pests addressed by quassia chips include some of the following:
- Aphids
- Pumpkin beetles
- Red spider mites
- Whiteflies
- Caterpillars
Along with being used as a mulch, quassia wood chips can also be boiled in water to create a solution that can be sprayed onto plant leaves to kill any insects that try to chew on them. The most effective method is to mix this extract with an insecticidal soap. This technique helps the quassia extract stick to the leaves more easily.
Ryania
Ryania is a pesticide of botanical origins and is produced from a tropical American tree known as Ryania speciosa. The active ingredient in ryania is ryanodine, but this chemical is not effective towards all insects. Ryania is only effective against the following pests:
- Fruit moth
- Codling moth
- Corn earworm
- European corn borer
- Citrus thrips
Ryania is an effective organic pesticide for stone fruit trees, citrus fruit trees, and corn fields, but since ryania is ineffective against boll weevils, cabbage maggots, and cauliflower worms, it isn’t a good choice for cotton or plants in the brassica family.
Sabadilla
Sabadilla is a botanical biopesticide that is created from the ground-up seeds of the sabadilla plant. Sabadilla is toxic to insects both through contact and through ingestion, and is effective against some of the following insect types:
- Squash bug
- Chinch bug
- Harlequin bug
- Stink bug
- Mexican bean beetles
- Leaf-eating thrips
It’s important to note that sabadilla is applied in a dust application, and that this dust can be very irritating to human respiratory systems even though it is only minimally toxic. Be sure to wear a mask while applying sabadilla to prevent discomfort.
Spinosad
Spinosad is another organic biopesticide that is created by soilborne pathogens. Spinosad is a popular additive to many commercial organic pesticides, and it is listed as a primary active ingredient in over eighty different insecticidal products.
Spinosad is effective as a pesticide against the following insects:
- Ants
- Spider mites
- Mosquitoes
- Thrips
- Leaf miners
- Fruit flies
As an insecticide, spinosad works as a paralytic poison. It causes the muscles of the insect to spasm uncontrollably until death occurs in 24-48 hours. While still a wet application, spinosad is highly toxic to beneficial pollinators. However, this toxicity is reduced once the applied solution has dried on the plant leaves.
Streptomycin Sulfate
In medicine, streptomycin sulfate is used as an antibiotic, and it was one of the first antibiotics used to successfully treat tuberculosis. In gardening, this chemical is used as an organic insecticide, fungicide, and algaecide. This antibiotic is currently used in 16 commercial organic pesticides.
Streptomycin sulfate is primarily used as:
- Treatment of commercial tobacco
- Treatment against fire blight in commercial apple and pear trees
Streptomycin sulfate works as a plant antibiotic against infections by inhibiting the offending bacteria’s ability to produce ribosomes in its cells. This antibiotic has low to no toxicity in most animals and humans. However, limited use is still recommended since this antibiotic is used in medicine and widespread exposure can increase human resistance to its effects.
Sticky Traps
Unlike biopesticides, sticky traps are a form of organic insect control that doesn’t release chemicals into the environment. Instead, sticky traps are placed around planting areas and kill insects by adhering them to the trap’s sticky surface.
Sticky traps are most effective for flying insects such as whiteflies and cabbage moths. However, sticky traps can also be placed around the base of plants to help catch crawling insects such as harlequin beetles or cutworms.
As an organic pesticide, sticky traps are good because they don’t result in any leech-off into the environment. However, the downside to using sticky traps is that they can potentially capture beneficial insects.
While sticky traps are effective at capturing flying insects or large crawling insects, these traps are not as useful for tiny or microscopic insects such as spider mites and leaf aphids.
Vitamin D3
Most organic pesticides are geared towards pests, but Vitamin D3 is used as an organic rodenticide. This vitamin is useful as a poison for the following rodent species:
- House mouse
- Roof rats
- Norway rats
Since both rats and mice can pose a significant risk to crops and chicken coops, Vitamin D3 is an effective agent to keep rodents out of gardening areas. It also has a minimal negative impact on the environment since it isn’t soluble in water and shows low toxicity levels for other wildlife.
Closing Thoughts
There are dozens of different types of popular organic pesticides that can be used safely in either home or commercial uses without worrying about long-term damage to the environment. These pesticides are also praised for their low exposure risk for humans, wildlife, pets, and livestock.
No matter what type of plants you’re trying to cultivate, there’s bound to be an organic pesticide out there that is perfect for your garden.
Here are Some of my Favorite Gardening Products and Tools
Thank you for reading this article. I hope you found it helpful for growing some new plants in your home or garden. Here are some products I like that I hope you’ll also find helpful. These are affiliate links, and I am compensated for referring traffic. But in all honesty, these are the exact product that I use or recommend to everyone.
Soil: For high-quality soil, I really like Fox Farm Ocean Forest. I do all my growing in containers and this soil has worked great for me. I like how they use nutrient-rich contents like earthworm castings, bat guano, and composted crab and fish.
Fertilizer: Currently I am using a seaweed-based organic fertilizer call Neptunes Harvest. This is a great milder fertilizer option if you want to use something organic. If you want a more powerful fertilizer, I recommend Fox Farm Liquid Nutrient Trio, lots of people have had great growing success with this product.
Pruning Shears: Pruning shears are one of the most useful gardening tools to have because it’s important to prune your plants to keep them healthy. The pruning shears I recommend are the Gonicc 8’’ pruning shears. I like them because they are built sturdy and work both on bigger and smaller plants, so you don’t need to have multiple pruning shears.
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