How to Make Homemade Insecticidal Soap for Plants

Castille soap next to green leaves for making homemade insecticidal soap
Use pure, natural soap and water when making insecticidal soap for your plants. (Antonio Gravate)

Thanks to insecticidal soap, controlling soft-bodied insects in your garden and on houseplants has never been easier!

Here’s a simple recipe for making your own homemade insecticidal soap using ordinary household ingredients.

Spray bottle spraying homemade insecticidal soap on plant leaves
Homemade insecticidal soap is all-natural and easy on plants. (Jupiterimages, Photo Images)

Homemade Insecticidal Soap Recipe

The simplest insecticidal soap is nothing more than a 2-percent soap solution. To make this at home, you will need:

  • Sprayer: Any clean spray bottle or garden sprayer will work fine for spraying insecticidal soap. Make sure the sprayer or bottle hasn’t been used for herbicides.
  • Pure Soap: Use a pure liquid soap, such as Castile, or all-natural soap. The active ingredient in insecticidal soap comes from the fatty acids in animal fat or vegetable oil, so it’s important to use the real thing. Don’t use detergents (which aren’t actually soaps), dish soaps, or any products with degreasers, skin moisturizers, or synthetic chemicals. Dr. Bronner’s Pure Castile Soap is usually pretty easy to find in stores or check your local natural-foods store for other options.
  • Pure Water: Tap water is fine for making insecticidal soap. If you have hard water, you may want to use bottled water to prevent soap scum from building up on your plants.

To make homemade 2-percent insecticidal soap, mix together:

  • 5 tablespoons soap to 1 gallon of water


  • 1 heavy tablespoon soap to 1 quart of water

Other ingredients can be added, such as crushed red pepper, canola oil, apple cider vinegar and garlic powder. (Photo illustration using images from Getty Images)

Homemade Insecticidal Soap Recipe Variations

Like any other home remedy, there are as many variations on this recipe as there are gardeners! You can also try:

  • Diluted Solution: If the spray causes damage or burns your plant foliage, cut the amount of soap in half and try a 1% solution. This is the concentration usually found in commercial sprays. The lighter solution might be less effective but is gentler on plants.
  • Cooking Oil: To help the solution stick a little longer, add two tablespoons of light cooking oil (such as corn, canola, olive, or safflower) per gallon of water to the mix.
  • Vinegar: To make a spray that also targets powdery mildew, add a teaspoon of cider vinegar per gallon of water to the mix.
  • Garlic or Pepper: To help repel chewing insects, add a teaspoon of ground red pepper and/or garlic per gallon of water to the mix.
  • Bar Soap: For a less-exact recipe, drop a bar of pure soap (such as organic bar soap or Ivory) into a gallon of water and leave it overnight. Remove the bar and shake well before spraying.

Further Reading

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  1. I have a four gallon spray pan. If I used the bar soap technique how long would I need to leave the soap soaking / how many soaps would I need for it to be effective as an insecticide?

  2. I have something eating on my asparagus ferns. It is stripping the plant and leaving just the stem. Will the soap solution help this problem?

  3. I dropped a bar of ivory soap in a gallon of water and left it until it all de-solved. Will this be to much soap for insecticide or should I add more water. I do not want to kill my plants.

  4. Betty

    Bar Soap: For a less-exact recipe, drop a bar of pure soap (such as organic bar soap or Ivory) into a gallon of water and leave it overnight. Remove the bar and shake well before spraying.

  5. when you spray the plants with the soap and water mixture , do you leave it on or rinse it off after some time?

  6. incidentally I’m on here because we have thrip on the lottie and this recipe looks cracking – any other suggestions greatfully received

  7. You don’t have to rinse off insecticidal soap, but it’s not a bad idea. The solution is only effective when it’s wet, anyway. Some plants (hawthorns, plums, cherries, and some tomato varieties, to name a few) are sensitive to insecticidal soap, especially if it’s overly concentrated or made with harsh soap. To reduce or prevent damage to plants, it wouldn’t hurt to rinse it off a few hours later, after it’s good and dry.

  8. My roommate left a pair of floating oil candles on the center deck post on my patio. It rained really hard last night and coated my plants with lamp oil.
    What can I use to clean the oil off my plants? My bonsai was directly underneath the oil shower, so all of it is soaked in oil. The leaves, trunk, roots, soil-every part of it is covered. Also, I need to wash the oil off my patio, since it is now flammable. The patio is surrounded by perennial plants that I want to keep alive. My bonsai has been rendered waterproof.

  9. Thanks so much, I needed something for my tomato plants but the stuff I bought kills 100 kinds of bugs and I am thinking do I want to put this on something I am going to eat? Thanks again.

  10. Looks like you’re using lavender scented soap rather than unscented. Any particular reason? BTW – I found my Dr Bronner’s at Whole Foods.

  11. Wondering what to use on my Tomatoes the bugs are eating right through them even before they ripen , this has been the worst year yet for my tomato plants !!

  12. Thanks for the help with recipe for insecticidal soap. I was just going to use Dawn dish soap and a drop of veggie oil, then I found your article. I am using it on my house plants before I bring them in for the winter. Thanks again.

  13. I stumbled upon this website and found that I was on the right track.
    I have a problem with fire ants. As a maker of hot salsa , I decided to try this to the ants. I threw about 4 or 5 hot peppers in the blender along with vinegar and dish soap. I strained the ingredients into a measuring cup and placed it into a spray bottle. I then got this idea about adding some vegetable oil to the mix and shook it well, to emulsify it. I figured that the hot pepper would stay longer on the ants because of the oil. I then went out to the ant nest and dug around to agitate those little b&*&##S and when they came streaming out I sprayed them and the ground,and little eggs too. The next day I came back looking for another fight only to discover that they were not there. I have done this on two nest. I will video tape the next one.

  14. Whenever I have a problem with fire ants I just boil some water and pour it right into the middle of the mound…. Works like a charm every time ha ha!!

  15. sir, i have problem in dissolving neem oil in water. it is written that using insecticidal soap we can dissolve neem oil in water..can u please suggest a soap and its concentration.i am from india

  16. Vince – If you are using cold pressed pure neem oil, I recommend using 1 tsp of liquid soap per 2.5 ounce of neem. Mix these two ingredients together BEFORE adding to WARM (or very warm) water. The quantity of water depends on the concentration you are attempting to achieve.

  17. I have a potted pinepple plant, a orange and lemon tree. I noticed that I have ants living in the soil. These plants are very large. What is the best way to evict these nuisancant pest?

  18. Am happy i found this site. In fact, I have being trying to control aphids and other insect in my okro farm but not working. I will try homemade insecticide and see what happens. thank you

  19. sir,
    Requested for help to continue my Rose trees. There is a problem in flowers. Insecticides ants eating the flowers. I have consulted more than 100 persons still I am not able found any solution. Please help me.

  20. What can I use to spray and kill wasp and hornets that nest in my bush hedge flower beds? Is there anything natural I can use. Thanks appreciate advise.

  21. hello. I made the insecticidal soap according to your directions and sprayed all of my vegetable plants top side and bottom side of leaves and the white flies were not phased by it. Any suggestions?

  22. Hi…need help for my 2yr old potted dwarf Mulberry plant. The leaves have some”bumpy spots” and there is a browning around the edge of the leaves..I’m afraid to spray anything,i.e. soap, neem oil etc. ( I killed my Meyer Lemon last winter by using neem oil on the leaves which had some critters..I really could use some Help here…..thanks so much !

  23. I have clover mites on my retaining wall by my rock flower bed and they are also all over my containers that have petunias in them. Will this soap get rid of them??

  24. I have Dr. Bonner’s Castile soap but it’s scented. Will this still work without harming the plants? Our lavender has Spitbugs all over, and I was advised to purchase an Insecticide soap.

  25. If you are going to use natural soap i.e. dervived from fat and caustic soda (saponification) and live in a hard water area, you are going to have problems with the soap reacting with the dissolved calcium (scum) – use clean rainwater straight off the roof which will be calcium-free, assuming that it is not a new roof with concrete tiles – this is the closest you will get to deionised water. Alternatively, get some EDTA (ethylene diamine tetraacetic acid, disodium form, commercially known as Versene and others) and mix a small amount, say a teaspoon to 1-litre, before you add the soap – you should get a nice clear soap solution.
    If you are not sure if your house mains water is hard or soft, get a small glass jar with a lid, half fill with tap water and flake in some soap. Shake well – soft water will give a good permanent lather and a clear solution, hard water will take a lot more soap flakes, will form scum and will not be a clear solution.

    Qualified to advise? Retired water scientist and engineer and avid gardener and rainwater harvester

  26. I have chigur bits. Is the a solution to get rid of the itch? I sprayed skin so soft baby oil on my feet, legs and arm. Have bit on elbow and feet. Can I and peppermint oil to it

  27. Sue, to get rid of the itch, put alcohol on the bite, like hand sanitizer. It will burn but only for a second and the itch will disappear.

  28. Can I use regular dishsoap and water or does it have to be pure soap? I have beans and a Hibiscus tree that are getting eaten alive.

  29. This is what i do for ‘MITES’ mainly and works for any other little black insect that eat on top or bottom side of the leaves which suck the life of your plants, trees, flowers ect..:

    Use any liquid soap or dish washing soap that is as close to unscented as possible. Just smell it, and make sure it does not have a heavy smell, if scented look for “EDTA” – (ethylene diamine tetraacetic acid) in the ingredients. Make sure there is NO CREAM, or type of HAND MOISTURIZER in the ingredient… then buy any ordinary PURE SOAP with FATTY ACIDS and OILS in the ingredients.

    1.) 5 liters of water to 5 not over-filled teaspoons of liquid soap.

    2.) Drop a bar of pure soap in the water and let it sit over-night.

    3.) Shake well and spray.. NO MORE MITES!!!!!

    4.) Or you can mix all the other ingredients for the other types of insects. 🙂 🙂 🙂

    Keep in mind that solution only works while “WET”, and is recommended to wash off the soap when plants, trees, ect.. dries off, … it will not harm but will leave a soapy taste if its edible 🙂

  30. What about Dawn dish soap with water? I got cherry tomatoes big boy tomatoes green peppers and yellow bell peppers. What every it is its got holes in the leaves of my plants.

  31. Hi there! I love using the organic/home-made remedies for not only growing flowers and veggies… I use home-made things on almost everything; washing the dog, showers, cleaning thr house, etc!!!! My question is this: instead of using a best of ivory that u mentioned; Do you think it’ll be ok if I substituted for Dawn dishing washing liquid? I wasn’t sure if I should use the Dawn until I can get some advice… I browsed through SO MANY websites that I’m a bit confused. to say the least!!!! Lol. Half of the people said, ‘Yes, that’s gine’ & others said to never use it.
    I’d appreciate a timely response!!!! Thanks again!

  32. I wanted to thank you for this information. I had a Hibiscus that was covered in aphids. I don’t like using chemicals and I’m on the thrifty side, so I tried putting a bar of Ivory soap in water and then spraying my plant for about three weeks. It has been a month since then and I’m getting beautiful flowers again and there is no sign of bugs!! Great advice and the whole treatment cost me about $1. Thank you!

  33. Thanks for the idea. Have white flies on my Kale. It would be nice if you answered more of the questions asked. Just saying!

  34. We used the ivory soap mix on my knock out roses earlier this year. I haven’t had to use a commercial spray on the roses all summer. In previous years I was constantly going to the store for more spray and it was costing a small fortune. My roses actually looked much better this year thanks to their ivory bath.


    32 ounce bottle
    2 parts rubbing aicohol
    5 parts water
    1 teaspoon ivory or castille soap

    So far this has been the most help without hurting my plants.

  36. Hi,
    I have one of those garden sprayers that you hook up to a hose. Using canola oil, dawn & water to control Aphids on my Crepe Myrtle, weeping something & hibiscus. Wondering how much of this combination to use in the sprayer since it will be diluted with hose water. Thanks so much.

  37. I had aphids on my hibiscus tree. I used dawn, water and vegtable oil to spray all the leaves. I aphids are gone but where there are buds where new leaves are coming, they are dropping off before they open up. The leaves are shiny from the oil, should I spray it off with water? I never had a problem with the tiny new bud of a leaf fall off. thank you so much.

  38. Thanks for the homemade bug spray recipe with variations, I’ve had the best results adding both the garlic and red pepper. Thanks also for explaining why I was getting a lot of soap scum when I used the Dr. Bronners soap! I was so dissapointed when I tried mixing the Dr. Bronners and ended up with a bunch of soap scum! From now on I’ll use deionized water or hopefully get some rainwater to use instead of the rock hard water that comes out of my homes pipes.

  39. I have white spots on hosta leaves that I believe are bird or squirrel droppings. I tried to clean with garden hose. Any ideas for cleaning without having to scrub each leaf.

  40. There are many different scents and versions of the Dr Bronner’s Castile soap that you recommended. Does it matter which one you use in the insecticidal recipe? I saw the lavender pictured above, is that the best one to use? Thanks so much for your help!!

  41. I have a gardenia tree I bring in for the winter. I have a problem with spider mites. What can I do and will the soap work for my tree?

  42. Even I have the leaves of my tomato and Marigold plants turn white and ultimately dry up because of these flies. Heart bleeds to see so many marigold buds not able to bloom into flowers because of leaves drying up. I have tried neem+detergent sprays a few times, but does not seem to help. Do not want to use any chemicals. What other options do I have?

  43. I have had a problem with a light green wormy bug on my geraniums that eats all the blooms. This year they are on my petunias and I tried commercial spray but they still are eating the plants. Any suggestions for a natural spray? Thanks!

  44. No problem with rabbits eating plants since I started spraying with Ivory soap dissolved in a spray bottle of water.
    Yea !!!!!

  45. I dip all plants I buy ..pot and a bucket of water with a hefty squirt of Dawn dishwashing soap. This has stopped white flies and aphids that seem to have been in the soil at the green house. I also save egg shells all winter and crumble them and put them around my cabbages and melons and this stops slugs and cut worms.

  46. I’m growing cherry tomatoes for the first time, and something’s eating the leaves( not the entire leaf, but making holes). Do I spray the leaves, or the stems and tomatoes also? They’re now small and still green?thank you!
    This is a great community.I’m new at this and would love to grow more of my own veggies, for cost and health reasons.

  47. I used the Dawn dishwashing liquid and water solution but did not rinse the leaves. They are now brown ,should I cut some of them back? btw, I also dusted cayenne pepper on the tomatoes themselves. No more bugs eating them. But afraid b/c the leaves are now brown.

    • Same thing happened to us. I think my roommate added too much soap and now it looks like everything is dying. Trying to figure out if I can save the plants.

  48. Does this only work as a preventative? Or would it help with a caterpillar and snail problem that has already started?

  49. That’s all well and good with these comments/questions but why are there no answers to the questions?
    What good are queries if there are no replies?

  50. Fungus gnats should be treated with a powdering of diatomaceous earth, work it in the top inch or two of soil. Fungus gnat larvae live in the soil eating fungus and roots so this is where you should target them. You can also follow up with Neem oil soil drench, usually 3-4 tbs per gallon. Just be aware the diatomaceous earth should fix your problem. Keep in mind you “may be” overwatering, if you allow the top couple of inches of soil to dry between waterings will drastically reduce fungus gnats naturally.

  51. as for the person who had bad chiggers; I have found that by dusting a little sulphur on your pants from the knees down before you walk into the yard will remedy the problem. Also, chiggers take a while to bite, so if you come inside, take your pants off in the tub and scrub your legs with dry or wet towel, you will be removing 90% of the chiggers. Put the used towels in wash, or in dryer for a while.

  52. I had not been successful with a cooking apple tree for three years (it is 3 metres tall and nearly as much spread width). I was told to look for mealy bugs and scaly mite. On finding the cottonwool like cluster here and there I thought I would try brushing with heater paraffin on the infected areas which worked so well that this year the tree was full of blossom and producing many apples. I might have been stupid by some peoples thoughts but for the first time many cookers are forming on my tree.

  53. Here is what I do to cure all pest problems in potting soil. When you buy new potting soil it will have pests in it. All brands do. Its unavoidable. So I bake it. At 350 degrees for at least 20 min. Watch carefully because some potting mixes can catch fire though I’ve never had that happen to any of mine. Also when buying new house plants be sure to remove them from their soil and rinse their roots off very well. Add the soil they came in to the soil you bake. Re pot them in the baked soil after it has completely cooled. Spray the plants themselves with Dr. Bonners castile soap. 1 tablespoon per quart of water. If over time you see your plants looking weak, not growing etc… look closely at them and their soil through a magnifying glass. Scratch the soil and watch to see any insect movement. If any are detected first try a soil drench with the soap mixture. Wait for the soil to dry and watch again for pests. If the soap mixture does not get rid of them then remove them, spray their roots then rinse then replant in fresh baked potting soil. This is the only true way of killing pests in your soil. Also I spray my house plants at least once a month with the Castile soap mixture. Be sure to keep them out of the sun till they completely dry.

  54. “Use a pure liquid soap, such as Castile, or all-natural soap. The active ingredient in insecticidal soap comes from the fatty acids in animal fat or vegetable oil, so it’s important to use the real thing. Don’t use detergents (which aren’t actually soaps)….or….synthetic chemicals.”

    It’s important to use the real thing?
    Why? Is there a genuine chemical reason to do so, or is this just some advice from a hippie gardner? This is obviously not a scholarly article because of the phrase “synthetic chemicals”

    • George George George, There is no contradiction nor redundancy in the term. From Scientific American : “Natural chemicals are produced by nature without any human intervention. Synthetic chemicals are made by humans using methods different than those nature uses, and these chemical structures may or may not be found in nature. This definition means a synthetic chemical can be made from a natural product (i.e. naturally derived). Note that in the food industry, “artificial” is used instead of “synthetic”. One of the surest ways to educate yourself is to (try to) educate others, isn’t it so?

  55. Fatty acid insecticide worked against the aphid infestation on my chilli plant. Had to give it a couple of good dousings, and the second time put paper over the soil. That has ended up a bit greasy and seems to have the slightest layer of mould loving it.

    I bought a synthetic aphid spray and they just shrugged that off, like the bottle warned they might. Another bottle, with a different ingredient, also said about immunity so I didn’t even buy it. But a fatty acid spray worked, and the plant’s even flowering again.

  56. Dawn Dish Soap

    3 tablespoons to a large spray bottle of cold Fawcett water worked killing Squash (stink) Bugs after 3 days in a row application with the bottle full on a 6 foot row of Butternut squash.


  57. Please let us know if this mix will harm bee’s, I doubt it would… should include this in your information, when this is posted to Face Book….more will pay attention to our Bee problem!!!

  58. I saw a black caterpillar eating my sedum plants. I would like to know:

    What is the name of this caterpillar?
    Is this a bad caterpillar?

    I will be glad to send you a picture of it

    Thank you

  59. Plz suggest best combination Of plant extract oils for controlling melaybug on grape. It should be 100 % residue free botanical products.

    Grape Farmer from India…

    • Hi, John,
      We haven’t used the specific product you mentioned, so we couldn’t compare the two.
      But we use this homemade insecticidal soap for all our plants and it does wonders!
      Good luck. 🙂

  60. I would like to use my miracle grow container for gEtting rid of spider mites as I have a very large area
    How much oil and soap should I put in the container each time I spray

    • Hi, Janet!
      To make homemade 2% insecticidal soap 5 tablespoons soap to 1 gallon of water or 1 heavy tablespoon soap to 1 quart of water.
      To help the solution stick a little longer, add two tablespoons of light cooking oil (such as corn, canola, olive, or safflower) per gallon of water to the mix.
      You will need to adjust the recipe to match the size of the container — use how many gallons of water you’ve poured to determine whether to multiply the number of tablespoons of cooking oil and soap by two, three, etc.
      Good luck. 🙂

    • Hi, Russell. You’re right! The American Chemical Society says gardeners have been using tobacco water as a natural pesticide for centuries because of tobacco’s content of toxic nicotine. Read more here: Thanks for sharing your tip with the community!


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