Does Dawn Dish Soap Kill Garden Pests? This ONE does …

by | Aphids, Earwigs, Insect Control, Insects, Pest Control, Plants and Trees

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Dawn dish soap is a well-known brand that’s probably sitting in your kitchen, but have you ever wondered if Dawn is helpful in cleaning up pests in your garden? Well, it turns out that…

Many common garden pests die when they come into direct contact with Original Scent Dawn dish soap diluted in water. The soapy water is thought to wash away a bug’s protective coating, so the pest dries out and dies. Once the soapy water has dried, it no longer has any effect on garden pests and should be rinsed off the plant.

Many gardeners praise the benefits of using Dawn dish soap for getting rid of pesky insects in their garden. Let’s take a look at what bugs you can kill with Dawn dish soap, how to kill these garden pests, and how to protect your plants in the process.

** If you live in the UK, Europe, Australia, or New Zealand, try this dish soap instead of Dawn dish soap. It’s made by the same company (Procter & Gamble) but is sold under another brand name

What bugs does Dawn dish soap kill?

Photo of an earwig on a dead plant
Photo of an earwig on a dead plant. Earwigs become garden pests when their population gets out of control.

Dawn dish soap can kill many garden pests, such as:

Bugs don’t have bones to support their body, like humans. A bug’s supportive structure is on the outside of its body and is called an exoskeleton. This exoskeleton protects the bug’s insides and gives it enough support to keep its shape and move around.

There is a waxy layer around this exoskeleton that keeps the bug moist inside and stops water from getting into the bug’s body. This waxy layer is very important in keeping the bug alive.

Researchers aren’t 100% certain why or how Dawn dish soap kills bugs, but they think that either:

  1. The soap washes off the bug’s protective waxy layer. After a little time, the bug loses too much moisture and dries out and dies.
  2. The soap has a poisonous effect on a bug’s nervous system and kills it, which is one of the most effective ways to kill bugs and is how many chemical pesticides work.

Diatomaceous earth is very effective at killing many of the above pests and more. Click here for a full list of bugs that DE kills, so you can decide which pest control will be better for you.

How to make Dawn dish soap spray to kill bugs

Photo of bottles of Dawn dish soap on a grocery store shelf

Dawn dish soap makes an easy and cost-effective alternative to the insecticidal soaps that you can buy from garden stores or Amazon, such as this ready-made concentrate.

Dawn dish soap must always be diluted in water before being sprayed onto plants. It will burn your plants if it isn’t diluted well enough.

Here’s the recipe to make Dawn dish soap insecticide:

Mix the water and dish soap well and pour it into a clean spray bottle or portable sprayer.


Never use dry soap, dishwasher soap, or laundry detergent instead of Dawn dish soap. These don’t kill bugs and can really damage your plants.

Only use the Original scent Dawn dish soap in the blue bottle, not any other Dawn product.

You need soft water to make good insecticide. You’ll know you have hard water if you see spots on the clean silverware washed in your dishwasher or stains on your newly washed clothes. If you have hard water in your home, use distilled or bottled water instead of tap water.

How to spray Dawn dish soap to kill bugs

For the solution to work well, it must come into direct contact with the bugs you’re trying to kill. Once your spray dries on the plant, it will no longer work.

Here’s a step-by-step guide on how to use Dawn dish soap insecticide for the best results:

  1. Check the weather forecast for rain – you want to apply the spray when you know there won’t be rain that day. If it rains before then, the rain will wash away the spray.
  2. Wait for early morning or early evening, when it’s not too hot outside. If it’s a sunny day, the sun will dry your Dawn spray very quickly and burn the plant. If you’re treating indoor plants, you can apply the spray at any time of the day or night.
  3. Start with any plant that’s showing signs of bug damage. Spray the plant from top to bottom with the Dawn spray. Make sure you cover the tops and undersides of its leaves, around the stem, and all its buds and flowers.
  4. If you see bugs, spray them directly with the solution. The insecticide must touch the bugs to work properly. Once it dries, it stops working.
  5. To protect your plants, rinse them down with fresh water once the spray solution has dried.
  6. Repeat this treatment every week or two until you get the pest problem under control.

This spray will kill any bugs that you have crawling on your plants but it won’t stop more bugs from coming in future. If new bugs arrive, use the Dawn spray to take care of them too.

Is Dawn dish soap safe for plants?

The Dawn insecticide is unlikely to damage your plants if you don’t use it often, but there are some plants that are more likely to get hurt by the spray.

You should never spray Dawn dish soap on the following plants:

  • Seedlings
  • New transplants
  • Plants with hairy or waxy leaves
  • Plants that are weak or drought-affected

Using the Dawn spray on any of these types of plants could break down the plant’s natural defenses and make them even more vulnerable to diseases and pests.

Plants and trees that don’t handle Dawn spray well are:

  • Azaleas
  • Begonias
  • Bleeding hearts
  • Cherry trees
  • Crown of thorns
  • Easter lilies
  • Fuchsias
  • Gardenias
  • Geraniums
  • Hawthorns
  • Horse chestnuts
  • Impatiens
  • Japanese maples
  • Lantanas
  • Maidenhair ferns
  • Mountain ash
  • Nasturtiums
  • Plum trees
  • Sweet peas

If you have any doubts, spray the Dawn solution on a single leaf and wait 24 hours to see if any damage occurs, like the leaf turning brown or wilting. If nothing happens, it’s probably safe to spray the entire plant without harming it.

Remember to rinse the plant with fresh water a few hours after spraying it with the Dawn spray, once the spray dries. Don’t spray and leave it on the plant indefinitely as the solution can remove the plant’s natural protective layers and make it more likely to be scorched by the sun.

If you need to treat plants that cannot handle Dawn dish soap or that have a bad reaction to your 24-hour test, there’s a good organic alternative for you…

Other soaps to use besides Dawn

If you have sensitive plants that you can’t spray with Dawn dish soap or you’re looking for an organic alternative, the best option is a good quality castile soap, such as this popular organic option on Amazon. Choose castile soap that has no added fragrances, chemicals, or additives.

To make a bug soap spray with castile soap, mix 6 tablespoons of castile soap in 1 gallon of warm water. Mix well and you’re ready to start spraying.

The good news is that this spray is gentle on your plants and let’s the good bugs live – like ladybugs.  

Final thoughts

Dawn dish soap is an effective and cheap option to kill many harmful backyard pests. Making sure that you dilute it, mix it well, and spray plants that can handle the soap spray will give you the best results.

Always rinse off the Dawn spray once it has dried as it won’t be much good as an insecticide and this will protect your plant.

I'm Monique. I love gardening and spending time in my backyard growing things. Here's where I share what I know about backyard pests and what to do about them, so you can enjoy your yard too.

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Monique loves gardening and spending time in her backyard, where she grows flowers, succulents, herbs, fruits, and vegetables.

Monique spends a lot of time researching how to protect her backyard from harmful pests and trying to attract beneficial insects and animals.

She shares everything that she learns and tests here at Backyard Pests.


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