12 Homemade Caterpillar Spray to Keep Plants Healthy

Homemade caterpillar spray is a natural remedy for caterpillars and their larvae. Some have the same odor and presence of pesticides as those nasty chemical sprays but without all the harmful chemicals. By making your caterpillar spray at home, usable inside and outside, you can keep caterpillars away from your plants.

Caterpillars are one of the most common pests found in gardens and can cause significant damage to plants. They are the larvae stage of moths and butterflies and feed on the leaves and stems of plants, leaving behind holes and strips of bare plant tissue.

If you have a garden, it’s important to control caterpillar populations to ensure that your plants remain healthy and lush. It can get really bad if you don’t know what to do to get rid of them. Using one of the effective homamde caterpillar spray is the easiest way to control caterpillars without spending money on chemical sprays or pesticides.

It’s a safe way to repel the bugs from your home without using chemicals that can be harmful when sprayed around young children, pets, and fish.

Homemade caterpillar spray is a natural way to protect your garden from caterpillar damage without harming your kids or pets; these sprays are safe for both your plants and the environment. If you find caterpillars eating through your plants, you can use any of the listed homemade sprays to take care of the problem.

Importance of caterpillar control in gardening

Pests and caterpillar control are essential to gardening and maintaining a healthy and thriving garden. Caterpillars are the larvae stage of moths and butterflies and can cause significant damage to plants in a very short period.

They feed on leaves, stems, and flowers, leaving the plants undeveloped. This affects not only the aesthetic appeal of the garden but also the overall health and productivity of the plants.

One of the primary reasons for the importance of caterpillar control is to prevent the spread of diseases. Caterpillars can carry and spread plant diseases from plant to plant as they feed. This can lead to the rapid spread of disease throughout the garden, causing significant damage and even death to the plants.

Importance of caterpillar control in gardening
Caterpillar eating plants

Another reason for the importance of caterpillar control is to protect the ecosystem in the garden. Caterpillars are an important source of food for many birds and other insects, and their absence can significantly impact the balance of the ecosystem.

By controlling the population of caterpillars, the gardener can ensure that the garden remains a healthy and thriving habitat for a diverse range of plants and animals.

Caterpillar control also helps to maintain the aesthetic appeal of the garden. Caterpillars can quickly defoliate plants, leaving them bare and unattractive. By controlling the population of caterpillars, the gardener can ensure that the garden remains lush and green, providing a beautiful and peaceful environment for the family and visitors.

Advantages of making homemade caterpillar spray

Making a homemade caterpillar spray has several advantages over commercial options. Here are some of them:

  1. Cost-effective: Commercial caterpillar sprays can be expensive, especially if you have a large garden. Making your caterpillar spray is much more affordable, and you can make it in large quantities to save money in the long run.
  2. Chemical-free: Commercial caterpillar sprays contain harmful chemicals that can harm humans, pets, and the environment. Homemade sprays use natural ingredients such as neem oil, vinegar, or soap that are safe for you and the environment.
  3. Customizable: When you make your caterpillar spray, you can adjust the ingredients to suit your specific needs. For example, if you have a lot of delicate plants that are sensitive to chemicals, you can use a gentler formula.
  4. Convenient: Making your caterpillar spray saves you time and effort. You don’t have to go to the store to purchase a commercial product, and you don’t have to worry about running out of spray when you need it. Mix the ingredients in your kitchen and store the solution in a spray bottle for easy application.
  5. Eco-friendly: Homemade caterpillar sprays are much more eco-friendly than commercial options. They don’t contain harmful chemicals that can leach into the soil and groundwater or release toxins into the air.

DIY caterpillar spray

Homemade Caterpillar Spray

Homemade caterpillar spray is an alternative to commercial insecticides that can be made using natural ingredients. These spray types effectively control caterpillar and other pest infestations in garden and farm crops. Here is a list of homemade caterpillar sprays that you can make at home:

Neem oil spray:

Neem oil is a natural and effective solution for controlling caterpillar infestations in your garden. It is a non-toxic, organic alternative to chemical pesticides and is safe for the environment and your plants. Here is how to make a homemade neem oil spray to control caterpillar infestations:

neem oil

Ingredients:

  • 1 cup of warm water
  • 2 tablespoons of neem oil
  • 1 teaspoon of liquid soap

Instructions:

  1. Fill a spray bottle with 1 cup of warm water.
  2. Add 2 tablespoons of neem oil to the bottle and shake it well.
  3. Add 1 teaspoon of liquid soap to the mixture and shake it again.
  4. Apply the solution to the affected plants, covering the leaves top and bottom.
  5. Repeat the application once a week until the caterpillar infestation is under control.

Note: It is important to test the solution on a small, inconspicuous area of the plant before applying it to the entire plant. Some plants are sensitive to neem oil, and it is always better to be safe than sorry.

This solution needs to be applied in the morning before the sun rises or late in the evening.  A homemade neem oil spray will control caterpillar infestations while keeping your garden healthy and chemical-free.

Garlic and onion spray:

Garlic and onion spray is a natural and effective solution to control caterpillar infestations in your garden. It is an eco-friendly and safe alternative to chemical pesticides that may harm the environment and plants.

Ingredients:

  • 2 medium-sized garlic bulbs
  • 1 medium-sized onion
  • 1 tsp cayenne pepper (optional)
  • 4 cups of water
  • 1 tsp dish soap

Process:

  1. Start by peeling and chopping the garlic and onion into small pieces.
  2. Add the garlic and onion pieces into a blender and pulse until they are finely chopped.
  3. Pour the chopped mixture into a pot and add 4 cups of water.
  4. Heat the mixture on medium heat for 10 minutes until it reaches a boil.
  5. Remove from heat and let the mixture cool completely.
  6. Strain the mixture through a fine mesh strainer to remove any solids.
  7. Add 1 tsp of dish soap to the strained liquid to help the spray stick to the leaves of the plants.
  8. If desired, add 1 tsp of cayenne pepper for extra potency.
  9. Pour the mixture into a spray bottle and apply to the affected plants.

This garlic and onion spray can be reapplied every 2-3 days or as needed to keep the caterpillar population under control. The strong aroma and taste of the garlic and onion will deter the caterpillars from feeding on your plants. Additionally, the cayenne pepper can act as a natural insecticide and will help repel the caterpillars. This spray is safe for edible plants and a great option for organic gardening.

Hot pepper spray:

Hot pepper spray is a natural and effective way to control caterpillar populations in the garden. The process is simple and involves mixing a hot pepper sauce with water and other ingredients to create a potent spray. Here’s a step-by-step guide to making hot pepper spray for caterpillars:

  1. Gather ingredients: To make hot pepper spray, you will need a hot pepper sauce, such as Tabasco, a gallon of water, a few cloves of garlic, and a tablespoon of dish soap.
  2. Mix ingredients: Combine the hot pepper sauce, water, garlic, and dish soap in a large spray bottle. Shake the bottle well to ensure that the ingredients are evenly distributed.
  3. Apply spray: Spray the hot pepper spray directly onto the plants’ caterpillar-infested leaves and stems. Cover the plant’s entire surface, including the leaves undersides.
  4. Repeat application: Reapply the hot pepper spray every few days until the caterpillar population decreases.

The hot pepper spray is a natural deterrent to caterpillars because the capsaicin in the hot pepper sauce is toxic. The dish soap helps to penetrate the caterpillar’s protective coating, allowing the hot pepper spray to be more effective. The garlic helps to repel other pests as well.

This hot pepper spray is safe for edible crops and will not harm other beneficial insects, such as honeybees and ladybugs. It is an eco-friendly alternative to chemical pesticides and will not harm the environment. It is easy to make and requires simple ingredients, making it accessible for all gardeners.

Vinegar spray:

Vinegar spray is a simple and effective solution for controlling caterpillar populations in your garden. Making this spray is easy and involves just a few ingredients.

Vinegar homemade caterpillar killer

Ingredients:

  • White vinegar
  • Water
  • Dish soap

Instructions:

  1. Mix 1 part white vinegar and 1 part water in a spray bottle.
  2. Add a few drops of dish soap to the mixture.
  3. Shake the spray bottle to mix the ingredients thoroughly.
  4. Spray the mixture directly on the caterpillars, covering all the affected areas.

The vinegar and dish soap will irritate the caterpillar’s skin, causing them to stop feeding and eventually die. It is important to note that vinegar is acidic and may harm beneficial insects in your garden or the environment.

For best results, spray the vinegar mixture in the early morning or late evening when the caterpillars are most active. Repeat the treatment every few days until the caterpillar population is under control.

However, it is not recommended to use it on plants with delicate leaves as the acidity in the vinegar can cause damage. Although, with regular use, vinegar spray can effectively control caterpillar populations in your garden, keeping your plants healthy and beautiful, but could damage your plants as well. 

Baking soda spray:

Baking soda spray is a popular and effective solution for controlling garden caterpillar infestations. This solution is simple to make and is an affordable alternative to chemical pesticides. Making a baking soda spray involves mixing baking soda and water, and a few other ingredients.

Ingredients:

  • 1 teaspoon of baking soda
  • 1 gallon of water
  • 1 teaspoon of dish soap
  • 2 tablespoons of essential oil

Process:

  1. Mix the baking soda and water in a large container until the baking soda is completely dissolved.
  2. Add the dish soap and vegetable oil to the solution and stir well to ensure the ingredients are fully combined.
  3. Pour the solution into a spray bottle and shake well before use.
  4. Spray the solution directly on the leaves and stems of the plants that are infested with caterpillars. Make sure to cover the entire plant, including the undersides of the leaves, where caterpillars often hide.
  5. Repeat the process every three to four days until the caterpillar infestation is controlled.

The baking soda spray breaks down the caterpillar’s protective outer layer, making it vulnerable to attack from natural predators. The solution’s soap and oil help penetrate the caterpillar’s body, causing it to dehydrate and die. This solution is safe for plants and other beneficial insects, making it an ideal choice for organic gardeners.

Diatomaceous earth:

Diatomaceous earth is a naturally occurring substance made from the fossilized remains of tiny aquatic organisms called diatoms. It is commonly used as a natural pesticide and insecticide, particularly for controlling caterpillars.

The process of using diatomaceous earth for caterpillar control is simple. The product is sprinkled on the soil or plant foliage where caterpillars are present, creating a barrier that the pests cannot crawl over without getting injured.

Homemade DE spray for caterpillars

The diatomaceous earth particles have sharp edges that damage the caterpillar’s exoskeleton and dehydrate them, causing death within a few days. The ingredient that makes diatomaceous earth effective against caterpillars is its composition. The fossilized remains of diatoms are composed of silica, which is abrasive to the delicate exoskeleton of insects.

The sharp edges of the particles damage the exoskeleton and cause the insect to lose moisture, eventually leading to death. You can also use DE as a spray. The process of making a diatomaceous earth spray is simple. Here are the steps:

  1. Mix the diatomaceous earth with water to form a thin paste.
  2. Pour the paste into a spray bottle.
  3. Add a few drops of liquid soap to help the mixture stick to the leaves and caterpillars.
  4. Shake the bottle to mix the ingredients well.

It is non-toxic to humans and pets, making it a safe and effective alternative to chemical pesticides. To use the spray, spray it on the infected leaves and caterpillars. The diatomaceous earth will start to work immediately, killing the pests as they come into contact with it. It is important to reapply the spray regularly, especially after heavy rains, to ensure the effectiveness of the treatment.

Horticultural oil: 

Homemade Horticultural oil spray is a solution made by mixing oils with water to control pests on plants.

Ingredients:

  • 1 cup of horticultural oil (e.g., canola, soybean, or cottonseed oil)
  • 1 tablespoon of dish soap (use a mild soap, not anti-bacterial)
  • 1 gallon of water

Process:

  1. Mix the oil and soap in a large container.
  2. Slowly add the water, stirring continuously to ensure the mixture is well blended.
  3. Pour the solution into a spray bottle.
  4. Spray the mixture on the leaves and stems of the plants, making sure to thoroughly coat the plants.
  5. Repeat the application every 7 to 14 days, or as needed, to control pests.

Note: It is important to test the spray on a small portion of the plant before applying it to the entire plant. Some plants may be sensitive to the oil and soap mixture, causing damage to the leaves. Also, apply the spray in the early morning or late evening to prevent damage to the plant from the sun.

Bt (Bacillus Thuringiensis) Spray:

Bacillus thuringiensis (Bt) is a natural bacteria commonly used as a pest control spray for plants. It is a safe and effective alternative to chemical pesticides and is often used by organic gardeners.  With this spray, gardeners can control pests without harmful chemicals. This method is also cost-effective and easy to make.

Bt caterpillar control

Ingredients:

  • Water
  • Bt spores (powdered form or liquid concentrate)
  • Liquid soap or dish soap

Process:

  1. Fill a spray bottle with water.
  2. If using powdered Bt fragments, mix 1-2 teaspoons of the powder with the water. If using liquid concentrate, add 2-3 teaspoons of the concentrate to the water.
  3. Add a few drops of liquid soap or dish soap to the mixture. The soap will help the solution to stick to the plants.
  4. Stir the mixture thoroughly to ensure that the Bt and soap are fully mixed with the water.
  5. Spray the mixture on the plants that are infested with pests. It is best to spray the plants early in the morning or late in the evening when the temperature is cooler to avoid scorching plants.
  6. Repeat the application every 7-10 days until the pests have been fully controlled.
  7. Store the remaining solution in a cool, dark place for future use. The solution will keep for up to 2 weeks.

Liquid soap helps to spread the Bt spray evenly and helps it stick to the plants. It is important to use a mild, unscented soap that is safe for plants.

Bacillus thuringiensis (Bt) is a natural bacteria toxic to specific pests but safe for humans, pets, and beneficial insects. The homemade Bt spray effectively and safely control pests in your garden without harmful chemicals.

Chilies and Garlic Spray:

Homemade Chilies and Garlic Spray is a natural pesticide that can be made easily at home with simple ingredients. It is a potent deterrent for a wide range of pests and insects, making it an ideal choice for gardeners and farmers.

Ingredients:

  • 4 cloves of garlic
  • 1 chili pepper
  • 1 cup of water
  • 1 tsp of dish soap
  • 1 tsp of vinegar (optional)

Process:

  1. Start by peeling and mincing the garlic and chili pepper.
  2. Add the minced garlic and chili pepper to a blender along with 1 cup of water. Blend until the mixture is well combined.
  3. Pour the blended mixture into a saucepan and heat it over low heat until it reaches a simmer.
  4. Allow the mixture to simmer for 10 minutes.
  5. Remove the mixture from the heat and let it cool completely.
  6. Add 1 tsp of dish soap and 1 tsp of vinegar to the mixture. Stir to combine.
  7. Pour the mixture into a spray bottle and shake well.

This chili and garlic spray can be used as a natural pest control spray for your plants. Use this spray on your plants to protect them from pests and insects. The combination of chilies and garlic acts as a natural deterrent, keeping pests at bay.

This homemade spray is safe for food crops and will not harm beneficial insects such as bees. Store the spray in a cool, dry place and use it within 1-2 weeks for best results.

 It can also be used as a marinade for meats or as a hot sauce for your favorite dishes. The spray can be stored in the refrigerator for up to 2 weeks.

Homemade Caterpillar Spray

Garlic and Peppermint Spray:

This homemade garlic and peppermint spray can be a natural pest repellent for plants. The strong scent of garlic and peppermint will deter pests from your plants, such as aphids, mites, and mosquitoes. Spray the mixture onto the leaves of your plants and repeat as needed.

Ingredients:

  • 10 cloves of garlic
  • 1 cup of water
  • 10 drops of peppermint essential oil
  • A spray bottle

Process:

  1. Start by peeling and crushing the garlic cloves.
  2. Boil the crushed garlic and water in a saucepan for 10 minutes.
  3. Remove the saucepan from the heat and let it cool to room temperature.
  4. Once the mixture has cooled, strain out the garlic pieces and add 10 drops of peppermint essential oil to the liquid.
  5. Pour the mixture into the spray bottle.
  6. Shake the bottle well to mix the ingredients.
  7. Your homemade garlic and peppermint spray is now ready to use.

This spray can be used as a natural insect repellent for plants in your garden. Spray the mixture on the leaves of the plants to keep insects away. It can also be used as a natural remedy for insect bites and stings by spraying the affected area. The garlic and peppermint in the spray have natural insect-repelling properties that help keep bugs at bay.

Soap and Water Solution:

This homemade soap and water solution caterpillar spray is a safe and effective alternative to harmful chemicals and can be used on edible plants and flowers. However, it is important to know that this method does not kill caterpillars but will repel them from your plants. 

Ingredients:

  • 1 tablespoon of dish soap
  • 1 gallon of water
  • Optional: 1 teaspoon of vegetable oil

Process:

  1. Mix the dish soap and water in a large spray bottle. Stir until the soap is fully dissolved.
  2. If using vegetable oil, add it to the mixture and stir until fully combined.
  3. Spray the solution directly onto the caterpillars, covering the entire surface of the insects.
  4. Repeat the process every 3-5 days or until all caterpillars are gone.

 The soap will smother the caterpillars, while the water will dilute the soap and make it easier to apply. The vegetable oil, if added, will help the soap adhere to the caterpillars, making it more effective.

Homemade Caterpillar Spray

Handpicking:

Handpicking caterpillars on plants is an effective and environmentally friendly method of removing caterpillars on your plants. This process involves physically removing the caterpillars from the plant using your hands. The downside to this method is that is can be time-consuming. Here is a step-by-step guide on how to hand-pick caterpillars on your plants:

  1. Inspect your plants: Begin by inspecting your plants for caterpillars. Look for caterpillar eggs and small caterpillars that may have just hatched. The eggs will appear as small clusters on the undersides of leaves and stems.
  2. Choose your tools: Gather the tools you need before starting the handpicking process. You can use gloves to protect your hands from the caterpillar’s skin and any pesticides or other substances on the plant: a bucket or a container to drown the caterpillars after you pick them off.
  3. Pick the caterpillars: Using your hands, gently grasp the caterpillar and pull it off the plant. Place the caterpillar into the container or bucket containing the vinegar solution. Repeat this process for all the caterpillars you find on the plant.
  4. Dispose of the caterpillars: Once you have collected them, dispose of them in a way that won’t harm the environment.
  5. Repeat the process: Repeat this every few days to ensure that you have removed all the caterpillars from your plants. It’s important to be consistent and persistent in your handpicking efforts to prevent the caterpillars from multiplying and causing more damage to your plants.

Hand-picking caterpillars on plants is a simple and effective way to get rid of caterpillars without using harmful chemicals. This method is environmentally friendly and helps conserve beneficial insects in the garden.

Homemade Caterpillar Spray FAQs

Can homemade caterpillar spray be harmful to other insects?

Homemade caterpillar sprays can be harmful to other insects. This is because many homemade sprays use broad-spectrum insecticides, which can kill a variety of insects, not just caterpillars.

Additionally, some of these sprays may not be selective, meaning they may also harm beneficial insects such as pollinators and natural predators of pests, disrupting the balance of the ecosystem.

It is important to carefully research and consider the potential impact on non-target species before using any type of insecticide, including homemade sprays.

Can homemade caterpillar spray be used on edibles?

homemade caterpillar sprays made with ingredients such as garlic and peppermint vinegar, diatomaceous earth (DE) and neem oil can be used on edibles, but it is important to follow the manufacturer’s instructions and guidelines for usage.

It is also recommended to wash the edible crops thoroughly before consumption. Keep in mind that not all natural ingredients are necessarily safe for consumption, so it’s important to be cautious and informed before using any homemade spray on food crops.

Is homemade caterpillar spray effective for all types of caterpillars?

Homemade caterpillar sprays may not be effective for all types of caterpillars. The effectiveness of these sprays can vary depending on the species of caterpillar and their stage of development. Some caterpillars may be more resistant to certain ingredients, such as garlic or hot pepper, while others may be more susceptible to other ingredients, such as BT or neem oil.

BT (Bacillus Thuringiensis) is a naturally occurring bacterium that is toxic to caterpillars and has been used as an effective control method for some species of caterpillars.

Neem oil is a natural insecticide derived from the neem tree and has been shown to be effective against a wide range of pests, including caterpillars.

Vinegar spray and DE (diatomaceous earth) spray can also be effective against caterpillars, but they may not be as effective as other methods.

It is important to remember that different species of caterpillars may respond differently to different control methods, so it is always best to research the specific species of caterpillar you are trying to control before selecting a control method.

Can homemade caterpillar spray be used on ornamental plants?

Homemade caterpillar sprays can be used on ornamental plants like garlic and peppermint. The vinegar spray, DE spray, and neem oil can all be used as a deterrent to caterpillar pests and will not harm the ornamental plants. However, it is important to research the proper dilution ratio and application method for each spray to avoid causing damage to the plants.

How often should I reapply the homemade caterpillar spray?

The frequency of reapplying the homemade caterpillar spray will depend on several factors, such as the severity of the infestation, the environmental conditions, and the effectiveness of the spray.

  • For garlic and onion sprays, it is recommended to reapply every few days to ensure maximum efficacy.
  • For hot pepper sprays, it is recommended to reapply every 5-7 days or as needed.
  • Vinegar sprays, it is recommended to reapply every 2-3 days or as needed.
  • For DE (diatomaceous earth) sprays, it is recommended to reapply every 2-3 days or as needed, depending on the weather conditions and the severity of the infestation.
  • For Neem oil sprays, it is recommended to reapply every 7-14 days or as needed, depending on the weather conditions and the severity of the infestation.

It is always best to observe the plants and reapply the spray as soon as you notice any signs of infestation.

Conclusion

Using homemade caterpillar spray has numerous benefits, including being cost-effective, environmentally friendly, and free from harsh chemicals. Additionally, many recipes use common household items, making it convenient and easy to prepare.

The effectiveness of these sprays varies depending on the ingredients used; however, many gardeners have reported positive results in controlling caterpillar infestations.

We encourage gardeners to try making their own caterpillar spray and incorporate it into their gardening routine. Not only will it help protect your plants, but it will also reduce the impact of harmful chemicals on the environment.

With a little experimentation, you may find that some of these homemade sprays are just what you need to keep your garden thriving. If you have not already tried making a homemade caterpillar spray, we encourage you to try it. You will be pleasantly surprised by the results. 

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