Does Soapy Water Kill Caterpillars? Alternative Methods

Soapy water is an effective pesticide against aphids, mealybugs, whiteflies, and many other insects and bugs but does It kill caterpillars? This is a common question; most people think soap water is good for killing caterpillars. So, I will tell you what soap water can do against these pesky animals.

The active ingredient in soapy water is potassium salt of fatty acids, which does not kill caterpillars. Soapy water does not contain enough PH to burn them up, but it does disrupt their breathing process and make them dizzy for some time.

Also, the waxy layer of caterpillars protects them from getting wet, making soapy water do less damage to them. Highlighted in detail below is why what soapy water can do to caterpillars and other various ways to get rid of them. 

Soapy water does not kill caterpillars

Soap water will not kill caterpillars; however, caterpillars will also typically crawl away from areas where they’ve been sprayed with soapy water because they don’t like the taste or smell of it.

Caterpillars are a type of insect that is known as lepidopteran. Caterpillars are often found on plants but can also be found in the soil around them. They eat leaves and other parts of plants to survive, and they thrive in warm weather when the temperature is above 65 degrees Fahrenheit.

Wetting your leaves with soap water will make it slippery for caterpillars to move on plants. Although, soapy water is effective at killing various insects like aphids, mealybugs, mites, and many more.

Does soapy water kill caterpillars

But soapy water won’t kill caterpillars because it’s not acidic enough to kill them when they’re already in their cocoons or chrysalises (those weird-looking sacs that look like cocoons). The pH level in soapy water is around 9 or 10, which is what a caterpillar needs to survive.

Because soapy water doesn’t kill caterpillars, it can’t prevent them from eating your plants and fruits. 

Will vinegar kill caterpillars?

Vinegar is an effective repellent for caterpillars and other caterpillars, but it’s not always the best choice because too much of it can kill your plants.

If you have a garden that doesn’t get much attention, vinegar could be a good option for getting rid of those pesky caterpillars. But if your garden is getting a lot of love from you, vinegar may not be the best solution.

Here are some reasons why:

  • Vinegar is acidic that can damage plants. You don’t want to use something that will harm your plants or animals.
  • Vinegar has a strong smell and taste, which won’t appeal to your pets or children when they come in contact with it (or you).
  • If you’re worried about damaging your plants or other critters with vinegar, try using neem oil spray, garlic oil spray, or peppermint oil spray. They are effective and will repel caterpillars away from your garden.  

However, if you are still interested in using vinegar to kill caterpillars in your garden, below is how to make your vinegar spray

You will need:

  • 2 cups of water
  • 1 cup of vinegar (white)
  • One tablespoon of dish soap
  • One teaspoon of garlic powder (optional)

Mix all ingredients in a spray bottle and shake well before using. Spray on the surface where you see a lot of caterpillars. They will be gone within days.

Homemade caterpillar spray

Garlic spray

Garlic spray is a natural insect repellent used to repel mosquitoes, flies, and gnats. It’s also great for repelling wasps, bees, caterpillars, hornets, and yellow jackets.

This easy recipe will have you in control of those pesky caterpillars any time of the year. Add three spoons of garlic to one cup of water in a spray bottle and use as you would any bug spray. It’s easy to make, smells great, and is good for your garden; plus, it’s made with all-natural ingredients. Follow the steps below.

If you have fresh garlic, crush 2 cloves of garlic with a blender and sieve it to remove particles; add 2 cups of water to the sieve garlic and pour in a spray bottle. Spray affected areas with this solution to keep caterpillars and other pests away from your garden.  

Hot pepper spray

Pepper spray is a natural insect repellant that works like a pepper spray. It is made from a spicy fruit called Capsicum or chili peppers. The capsaicin in chili peppers is a deterrent to insects, but it also affects the human body by irritating the eyes, nose, and throat.

If you’re looking for a way to deter those caterpillars from feasting on your garden, look no further. This homemade caterpillar spray is sure to do the trick. 


  • 3 tablespoons of hot pepper sauce (preferably Tabasco)
  • 1 cup of water
  • 2 tablespoons of vegetable oil


1. Mix all ingredients in a small bowl. Make sure that there are no lumps or chunks in the mixture and that the water is completely mixed in.

2. Pour into a spray bottle, and enjoy your new deterrent. 

Neem oil spray

Neem oil spray is a great way to keep your home and garden pest-free, and it’s also a great way to help your plants grow. This natural pesticide comes from the neem tree, which is native to India and is one of the most effective insecticides.

You can use it as a spray or pour it into a container and set it out in your garden or yard. The neem oil will kill any insect that comes into contact with it, so you won’t have to worry about insects taking advantage of your plants. You can make a neem oil spray by following the process below.

  1. Mix 1 cup of water and one teaspoon of neem oil. If you want to make it less concentrated, you can add more water, but don’t use too much. 
  2. Pour the mixture into a spray bottle and shake well before each use.
  3. Spray the mixture on your plants at least once every two weeks and more often if you notice any caterpillars.

Best insecticide for caterpillars

Garden Safe BT Worm & Caterpillar Killer Concentrate

Garden Safe BT Worm & Caterpillar Killer concentrate is a particularly potent killer of worms, moths, and other crawling pests that feed on the roots and crowns of plants. It will kill all stages of worms, including grubs, white grubs, and bulb flies. This is the only organic worm killer with no para-phenylenediamine, which causes skin irritation to many people.

Apply as a spot spray for caterpillars in the middle of the day or as a heavy drip to cover all potential caterpillar harborage areas of your plants. To ensure that birds, pets, and children do not come into contact with the poison, wear a safety mask when spraying this product on your plants.

Southern AG Caterpillar Control

Best insecticide for caterpillars

Southern AG is an effective and environmentally safe insecticide for the control of a variety of pests. It controls caterpillars, aphids, beetles, and flies in various crops, including strawberries, tomatoes, peppers, beans, and eggplants. This caterpillar control guaranteed ongoing protection against various types of caterpillar infestations. 

BioAdvanced Vegetable and Garden Insect Spray

Best insecticide for caterpillars

BioAdvanced Vegetable and Garden Insect Spray is the perfect natural way to protect your fruits and vegetables from bugs. It’s safe for both plants and kids, plus it’s organic, biodegradable, and highly effective. This product is formulated to control target pests, such as cabbage loopers, root maggots, and cabbage worms.

This unique formula contains two types of natural insecticide, pyrethrum, and neem. This insecticide can be used to protect your plants from worms, grasshoppers, caterpillars, and more. Apply this insecticide directly to the leaves of plants in your yard or garden.

What other ways are there to kill caterpillars?

If you have caterpillars in your backyard, you’re not alone! Caterpillars are a common sight in the fall, and they can be pretty annoying, but they’re also pretty easy to get rid of. Check out these natural ways to get rid of caterpillars:

Use Citrus oil

Citrus oil is a natural way to repel caterpillars. It works by making them smell and taste bad, which will keep them from coming back to your yard later on.

To use citrus oil for this purpose, mix it with water in a spray bottle and spray it on the affected area. The mixture should be sprayed regularly until the caterpillars are gone from your garden or yard.

There are three essential oils that work best for getting rid of these pests: lemon, grapefruit, and orange.

Use sticky traps

You can use sticky traps if you don’t want to use pesticides. They are usually made of paper or plastic wrapped around your plant’s stem.

The caterpillar will crawl onto the trap and get stuck. This method is effective but requires maintenance because the caterpillar will have to be removed from the trap every few days and discarded.

You can also put these sticky traps around the garden to prevent them from getting onto your plants and vegetables. 

Use vinegar solution

Use an apple cider vinegar solution to get rid of caterpillars. Vinegar will kill the caterpillar on contact and make them pupate in their cocoon so that they cannot hatch as adults next year.

  1. Put 2 cups of water in a large bowl.
  2. Add 1 cup of white vinegar and ½ cup of baking soda, stirring them until the baking soda is dissolved.
  3. Place this mixture in a spray bottle, or use a mister.
  4. Spray your plants regularly for the next few days to see if the caterpillars are gone! If you’re having problems with caterpillars, there are a few options for getting rid of them.

Apply a Bacillus thuringiensis (Bt)

If you have caterpillars in your garden, the easiest way to get rid of them is with a chemical called Bacillus thuringiensis. This naturally occurring bacterium has been used for many years to control pests like caterpillars and aphids.

It’s safe to use around children and pets and will kill any caterpillars or moths that come into contact with it. You can apply it directly to the caterpillar’s body or spray it on plants that are attractive to them. If you use the spray, start with a small amount of Bt and add more if needed.

The instructions on the packaging will tell you how much to apply. If you don’t have any handy, mix a teaspoon of Bt powder with some water and give it to your caterpillar!

Use neem oil

Neem oil is a natural remedy that can kill various pests and insects, including caterpillars. It is a plant-based pesticide derived from the Neem tree’s seeds. The tree is native to India and has been used as a medicinal herb for thousands of years.

Neem oil contains chemicals called azadirachtins that are extremely effective at killing insects. It works by interfering with the process that insects use to regulate their body temperatures, causing them to overheat and die from dehydration or starvation (depending on how much neem oil they use).

To apply neem oil safely around your garden, mix two teaspoons with 1 gallon of water in a spray bottle before using it to kill caterpillars. You can also apply it directly on leaves where you see them congregating together; make sure not to expose yourself directly under any leaves while doing this!

Use Diatomaceous earth

The easiest way to get rid of caterpillars is to use diatomaceous earth, a safe and effective way to eliminate pests without harming them.

Diatomaceous earth (DE) is a natural substance used for centuries as an insect control product. It’s made from fossilized remains of ancient aquatic organisms called diatoms. The powdery substance is mined from sedimentary rock deposits on the shores of lakes and rivers.

Diatomaceous earth is used as a pesticide because it kills insects by destroying their protective outer skin and exposing their insides. It also absorbs moisture, killing eggs and larvae when exposed to it.

You’ll need the following:

  • 1/2 cup of diatomaceous earth
  • 1 cup hot water

Mix the two in a bowl until well mixed, and spray it on the affected areas with caterpillars. You can also sprinkle the DE directly on caterpillars to kill and ward them off in your garden. 

Handpick caterpillars

Handpicking caterpillars is a great way to get rid of them. This is the best way to eliminate caterpillars because it is the most effective and least harmful. You can use a pair of tweezers or a small needle-type tool to grab the caterpillar and remove it from your plant.

This method will also be easier on them than if you were to try and sweep them off with a broom or other tool. You can throw them in a vinegar solution to drown them or directly into the trash or compost bin.

Use garlic spray

Garlic spray is a natural way to get rid of caterpillars, and it’s easy too. You must get some garlic and spray it on the spots where you see the caterpillars. This will prevent them from coming back.

Garlic spray is made by mixing one part water with three parts garlic juice (or one part water and two parts oil). You can usually find this product at any grocery store near the herbs and spices section, or you can make it yourself by adding garlic juice to water. Add this solution to your garden every few days until you no longer see caterpillars in your garden.

Grow plants they hate

If you have caterpillars, there are a few natural ways to get rid of them. Plants they hate include rosemary, mint, and basil.

These plants repel many insects, including fleas and caterpillars. You can plant it in an indoor pot or your garden. 

Other plants include Mint, Chives, Oregano, Rosemary, Bees Balm, Beeswax, Cabbage, Carnations (especially pink), Chamomile, Chrysanthemums (especially yellow), Dandelions (especially yellow), Easy Geraniums (especially red), parsley, dill, and fennel.  

Dill is easy to grow in pots or containers and will provide fresh dill throughout the year. Fennel is a perennial plant that grows best in full sun and does not need much water once it gets established in the ground.

Introduce natural predators

If you don’t want to spend money on pesticides or hire someone to spray your yard, try setting up small areas where predators can hunt down the caterpillars before they reach maturity.

For example, if you have chickens or ducks on your property, they help get rid of these pests. It’s also worth noting that some butterflies will eat caterpillars, so if you have any hanging around, they might be eaten by butterflies instead.

You can also introduce natural predators of caterpillars into your gardens, such as ladybugs and lacewing larvae. The insects will eat the caterpillars, but you can also use them to help control aphids. If you don’t want to attract more insects and other pests, you can use neem oil to keep them away.

Encourage birds in your yard.

Birds are an excellent way to get rid of caterpillars. Birds eat them and their larvae, so you won’t have to worry about further damage or pests. You can encourage birds in your yard by providing them with food and water, like bird seed, and nesting materials like pine needles or branches. You can also make a small hole in an old tree trunk and place some sticks inside it so birds can safely nest there.

How to prevent caterpillars from eating your plants

Caterpillars are one of the more common things when growing plants in your garden. They’re not necessarily bad, but they can be frustrating when they start eating all your plants. Luckily, there are ways to prevent caterpillars from eating your plants.

  1. Get rid of any weeds around your plants
  2. Keep an eye on the weather
  3. Watering plants regularly and removing leaves that have dried out are good ways to keep caterpillars from eating your plants

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