Plants are a beautiful addition to any home, but sometimes they can fall prey to infestations by pests such as mites, aphids, and fungus gnats. While many chemical treatments are available, I prefer to use natural homemade insecticides to avoid the potential negative effects of these chemicals on their plants and my own living environment. In this article, we’ll explore some of the most effective natural insecticides for plant infestations and discuss which infestations they best address.
Types of Infestations for Indoor Plants
Indoor plants can be affected by a wide range of pests, each with their own unique set of symptoms and treatments. Some of the most common infestations for indoor plants include:
- Spider Mites: These tiny arachnids are a common problem for indoor plants, particularly in dry environments. Infected plants will often show signs of leaf discoloration, and may develop webs on the undersides of leaves.
- Mealybugs: These soft-bodied insects are often found in large groups on the stems and leaves of indoor plants. Infected plants may show signs of stunted growth, yellowing leaves, and a sticky residue on the leaves and stems.
- Aphids: These small, pear-shaped insects can be found on the leaves and stems of indoor plants. Infected plants may show signs of wilting, stunted growth, and distorted leaves.
- Fungus Gnats: These small, dark-colored flies are often found around indoor plants, particularly overwatered ones. Infected plants may show signs of yellowing leaves and stunted growth.
Natural Remedies for Plant Infestations
1. Neem Oil
Neem oil is fantastic natural pesticide that can be used to control a wide range of plant pests and diseases. I’ve used it myself to fight against a variety of infestations. Neem oil is extracted from the seeds of the neem tree, which is native to India and has been used in traditional ayurvedic medicine for centuries. Neem oil contains several compounds that have insecticidal and fungicidal properties, making it an effective solution for a variety of plant infestations.
Neem oil can control pests such as aphids, spider mites, whiteflies, mealybugs, and scale insects. It disrupts the insect’s hormonal system and interferes with its feeding and reproduction, ultimately leading to its death. Neem oil can also control fungal diseases such as powdery mildew, black spot, and rust. It works by disrupting the fungal cell membrane, preventing the spores from germinating and spreading.
When used correctly, it is safe for humans and pets. Of course, please consult your vet about your specific pet! It is also biodegradable and does not leave harmful residues in the environment. However, it is important to note that neem oil can harm bees and other pollinators.
To use neem oil as a pesticide, dilute it according to the instructions on the label and apply it to the affected plants using a spray bottle or garden sprayer. Be sure to cover both the tops and bottoms of the leaves and stems and branches. For best results, apply neem oil every 7-14 days, depending on the severity of the infestation. Be careful, as the oil can burn the leaves on plants. So dilute it WELL. Start with a little bit and work your way up as you intuitively see fit.
2. Jalapenos & Chili Peppers
Using jalapenos as a pesticide for plants can be quite effective against certain types of pests. I’ve personally used jalapeno peppers to help control infestations of aphids, spider mites, and other small insects.
To make a jalapeno pesticide, you’ll need to blend several peppers with a few cups of water in a blender. I then strain the mixture to remove any large bits of pepper, then pour the liquid into a spray bottle. You can then apply the spray directly to the soil of affected plants, being sure to cover both the tops and bottoms of the leaves. Remember to dilute it more at first and then work your way up feeling it out since different plants can be more sensitive than others.
The capsaicin in jalapeno and chili peppers is what makes them effective as a pesticides. It irritates the insects’ mouths and digestive systems, ultimately leading to their death. However, it’s important to note that jalapeno spray can also irritate your skin and eyes, so be mindful of that when handling and applying it.
3. Insecticidal Soap
Both traditional and insecticidal soaps can be effective against certain types of pests. I have used both types to fight against a variety of infestations, including aphids, spider mites, whiteflies, and mealybugs.
Traditional soaps, such as castile or dish soap, work by breaking down the protective coatings on the insects’ bodies, causing them to dehydrate and die. Insecticidal soaps, on the other hand, are specially formulated with potassium salts of fatty acids and are more effective at killing pests while being less harmful to plants.
It’s important to use a gentle soap and avoid spraying during the heat of the day or in direct sunlight, as this can burn the leaves of the plant. Additionally, always follow the instructions on the product label for proper dilution and application.
4. Diatomaceous Earth
Diatomaceous Earth is another natural solution that can be used as a pesticide for plants. I have used it to prevent pests like roaches and bed bugs. But it also helps against slugs, snails, and other types of crawling insects. This substance is made up of fossilized remains of tiny aquatic organisms called diatoms and works by puncturing the exoskeletons of insects, causing them to dehydrate and die.
When using Diatomaceous Earth, you should sprinkle a light dusting on the soil around the plant or on the leaves and stems of affected plants. Be sure to wear a mask to avoid inhaling the fine dust particles, and keep in mind that it can also harm beneficial insects like bees and ladybugs.
It’s important to note that Diatomaceous Earth is not effective against all types of pests, particularly those that fly or jump. In these cases, using a combination of Diatomaceous Earth and another natural solution, such as insecticidal soap, may be more effective.
5. Sticky Traps
Sticky traps are a simple and effective way to control infestations of flying pests, such as fungus gnats. They work by attracting pests to a sticky surface, where they become trapped and unable to reproduce. Sticky traps can be purchased online or at garden centers, and should be placed near affected plants.
6. Beneficial Insects
Certain insects, such as spiders, ladybugs, and lacewings, are natural predators of many plant pests. Introducing these insects into your indoor garden can help control infestations of pests such as aphids and mealybugs. Beneficial insects can be purchased online or at garden centers, and should be released directly onto affected plants.
7. Essential Oils
I have found that essential oils can effectively repel or kill insects that damage plants, such as aphids, whiteflies, and spider mites. Not only are essential oils less toxic than synthetic pesticides, but they also smell great and sometimes even promote plant growth. Here are some types of essential oils that you can use as a pesticide for your plants:
- Peppermint oil: Peppermint oil has a strong scent that repels many insects, including ants, aphids, and whiteflies.
- Citronella oil: Citronella oil is commonly used as a mosquito repellent, but it can also repel other insects that damage plants, such as thrips and leafhoppers.
- Tea tree oil: Tea tree oil has antifungal and antibacterial properties, making it useful for treating plant diseases caused by fungi or bacteria.
- Eucalyptus oil: Eucalyptus oil can repel insects and also has antifungal properties, making it useful for preventing fungal infections in plants.
- Lavender oil: Lavender oil has a calming scent that can repel insects, including moths and mosquitoes.
You can use essential oils as a pesticide for your plants in a few different ways. Here are some methods:
- Spray: You can dilute a few drops of essential oil in water and spray it directly on your plants. Make sure to shake the bottle well before spraying and avoid spraying in direct sunlight or on hot days.
- Soak: You can soak cotton balls or cloth in a diluted solution of essential oil and water and place them near your plants to repel insects.
- Diffuse: You can use a diffuser to disperse essential oils into the air around your plants, which can help repel insects and prevent the spread of plant diseases.
- Mix with other natural ingredients: You can mix essential oils with other natural ingredients, such as vinegar or dish soap (listed here), to create a more effective pest control solution.
Always do a patch test on a small area of your plants before using essential oils as a pesticide to ensure that your plants don’t have an adverse reaction. Additionally, it’s important to use caution and follow proper dilution guidelines when using essential oils, as they can be harmful if used in excessive amounts!
8. Horticultural Vinegar
Horticultural vinegar is a natural alternative to traditional herbicides, and can be used to kill weeds and other unwanted plants. It can also be used to control certain types of plant pests, such as spider mites and aphids. To use, dilute the vinegar in water according to the instructions on the label, and spray it directly onto the affected plants.
9. Cinnamon
Using cinnamon as a pesticide for plants is a natural and effective way to control certain plant infestations. Cinnamon can also repel or kill some insects that damage plants, such as gnats, ants, and spider mites. I like using cinnamon as a preventative antifungal and antibacterial homemade insecticide.
You can use cinnamon in a few different ways, such as sprinkling it on the soil around your plants, mixing it with water to create a spray, or adding it to the soil to prevent fungus from growing. Cinnamon is a safe and natural alternative to synthetic pesticides, and it can help protect your plants without harming the environment or exposing you to harmful chemicals. Mix the cinnamon with the other ingredients listed above for the strongest effect.
10. Other Plants!
- Nicotine (Tobacco): The tobacco plant contains nicotine, which can act as a natural insecticide. Nicotine is a toxic chemical to many insects, and it can be extracted from tobacco plants and used as a pesticide. However, it’s important to note that nicotine can also be harmful to humans and other animals, so it should be used with caution and only as directed
- Chrysanthemum cinerariifolium: Also known as the pyrethrum daisy, this plant contains natural insecticidal compounds called pyrethrins. Pyrethrins are commonly used as a natural pesticide in commercial and household products to control various insects, including mosquitoes, flies, and fleas.
- Marigolds: Marigolds contain compounds that can help repel some common garden pests. The marigolds’ roots produce alpha-terthienyl, a chemical that can repel nematodes, a type of soil-borne pest that can damage plant roots. Additionally, the strong scent of marigolds can deter some insects, such as whiteflies and aphids, from feeding on nearby plants.
- Calendula: Calendula contains a natural insecticidal compound called linalool, which is toxic to some insects, such as whiteflies, spider mites, and aphids. Calendula can also attract beneficial insects, such as ladybugs and lacewings, which can help control pest populations in your garden.
When using natural remedies for plant infestations, it’s important to remember that not all remedies are effective for all types of pests. Use caution when applying any treatment is also important, as overuse can damage or kill your plants.
In addition to using natural remedies for plant infestations, there are also steps you can take to prevent infestations from occurring in the first place. These include keeping your plants well-watered but not overwatered, keeping the humidity level in your home at an appropriate level, and regularly inspecting your plants for signs of pests.