Home Improvement Expert Danny Lipford

How to Make Homemade Insecticidal Soap for Plants

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Spray bottle and natural soap

Use pure, natural soap and water when making insecticidal soap for your plants

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.

Homemade Insecticidal Soap Recipe

The simplest insecticidal soap is nothing more than a 2% 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% insecticidal soap, mix together:

  • 5 tablespoons soap to 1 gallon of water

OR

  • 1 heavy tablespoon soap to 1 quart of water
Containers of garlic, pepper, vinegar, and cooking oil

Other ingredients that can be added to homemade insecticidal soap

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 Information



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27 Comments on “How to Make Homemade Insecticidal Soap for Plants”

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  1. Louis Finsand Says:
    August 5th, 2012 at 5:16 pm

    Does Fels Naptha work as an insecticidal soap?

    Thank You.

    Louis Finsand

  2. Michael Tulloch Says:
    September 13th, 2012 at 2:10 pm

    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?

  3. Dianne Says:
    June 5th, 2013 at 12:14 am

    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?

  4. Beck Delvecchio Says:
    May 27th, 2014 at 12:07 pm

    Is Castillo soap solution ok on vegetables?

  5. Betty Nance Says:
    May 29th, 2014 at 8:51 pm

    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.

  6. Karen Says:
    June 6th, 2014 at 12:20 pm

    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.

  7. Charlie Reid Says:
    June 9th, 2014 at 7:55 pm

    If you can use Ivory bar soap, can you use the Ivory soap flakes?

  8. RAJ PATEL Says:
    June 20th, 2014 at 2:17 pm

    I made & use Homemade Insecticidal Soap for Rose Plant Work good,Thank You Sir

  9. jenny house Says:
    June 28th, 2014 at 7:14 am

    will this solution keep the mice away in my greenhouse?

  10. Allen Peek Says:
    June 28th, 2014 at 8:52 am

    Thanks you have been very helpful.

  11. raetta kimbel Says:
    July 3rd, 2014 at 6:58 am

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

  12. Alex Says:
    July 3rd, 2014 at 5:14 pm

    asparagus beetle, clear them by hand each day or spray them, buggers!

  13. Alex Says:
    July 3rd, 2014 at 5:18 pm

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

  14. Beth schuler Says:
    July 8th, 2014 at 5:54 pm

    In response to r.kimbels post; I think you’re supposed to rinse off the plant after a few hours

  15. Julie Says:
    July 9th, 2014 at 3:20 pm

    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.

  16. Jean-pierre Says:
    July 18th, 2014 at 7:29 pm

    Using the bar method, how many gallons would one whole bar make?
    thank you

  17. L. Brown Says:
    July 28th, 2014 at 4:13 pm

    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.
    Help!

  18. Lana copeland Says:
    August 1st, 2014 at 2:37 pm

    Will ivory bath wash do.

  19. Dennis Fane Says:
    August 2nd, 2014 at 4:44 pm

    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.

  20. JohnHerrick Says:
    August 8th, 2014 at 6:33 pm

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

  21. Christina Says:
    August 22nd, 2014 at 11:33 am

    Do I need to spray the insecticidal soap into the soil as well.. they are sucking the life out of my potted flowers!

  22. susan Says:
    August 23rd, 2014 at 5:04 am

    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 !!

  23. Patti T. Says:
    September 21st, 2014 at 8:29 am

    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.

  24. jim Says:
    September 30th, 2014 at 1:37 pm

    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.

  25. Amanda hughes horan Says:
    October 23rd, 2014 at 9:12 pm

    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!!

  26. Bonnie Bond Says:
    November 13th, 2014 at 12:28 am

    Thanks for the help. The silky spider type webs are gone!

  27. Mohammad Says:
    November 19th, 2014 at 4:02 pm

    Will Unscented Pure Vegetable Glycerine soap work okay?

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