Healthy houseplants tolerate pests better than unhealthy ones.

How to Kill the Bugs in Your Household Plants With Fels Naptha

by Marylee Gowans

When household plants become infested with bugs, don’t reach for expensive chemical-filled pesticides. Instead, create your own with Fels-Naptha. Fels-Naptha is a laundry bar soap that, for over 100 years, has been used to remove stains and grease from clothing. Fels-Naptha doesn’t contain bleach, degreasers or fragrances, which makes this affordable and versatile product ideal for homemade insecticidal soap. Insecticidal soaps control soft-bodied pests -- such as aphids and spider mites -- and won’t pollute your home with harsh toxins that could potentially harm your family.

Use a cheese grater to shave about 1-inch off the bar of Fels-Naptha soap.

Bring 1 quart of soft water to a boil on your stove. Hard water contains minerals that will interfere with the soap spray.

Remove from heat and dissolve the piece of soap you shaved off the bar while stirring with a wooden spoon.

Allow the solution to cool to room temperature. Transfer the cooled solution to a glass jar that has a lid. This is the concentrate mixture.

Pour 1 quart of soft water in a spray bottle when you are ready to treat the houseplants. Add 1 teaspoon of the concentrated soap solution and shake the spray bottle gently until the water and soap are well mixed.

Spray the top and underside of the leaves with the homemade soap spray to control the soft-bodied pests infesting the houseplant. Reapply the spray at weekly intervals until you have controlled the pests.

Items you will need

  • Cheese grater
  • Bar of Fels-Naptha soap
  • Pot
  • Wooden spoon
  • Glass jar with lid
  • Spray bottle


  • Test the homemade soap spray on a small area of the houseplant. If no damage appears after two or three days, treat the plant as planned.


  • Never spray water-stressed plants with pesticides.
  • Avoid applying the homemade soap spray to plants with hairy or waxy leaves.

About the Author

Marylee Gowans has written about gardening for both online and print publications. She attended the University of Akron, graduating with a Master of Fine Arts in creative writing. In 2009, she received master gardener certification from the Master Gardeners of Summit County, Ohio.

Photo Credits

  • Jupiterimages/BananaStock/Getty Images