How to Use Insecticidal Soap on Plants
By: Julie Day
Problems with spider mites? Give your plants a bath with insecticidal soap! Made from a simple soap solution, insecticidal soap is a greener, more eco-friendly approach to insect problems in the garden and on houseplants. You can buy insecticidal soap in a ready-to-use spray or make your own using this simple recipe.
Insects Affected by Insecticidal Soap
Insecticidal soaps work by disrupting the cell membranes and dissolving the natural waxy coatings found on soft-bodied insects including:
- Immature leafhoppers
- Mealy bugs
- Spider mites
- Immature white flies
- Eggs and pupae of other insects
Eco-Friendly Advantages of Insecticidal Soap
If made and used correctly, insecticidal soap is more eco-friendly than traditional insecticides since it:
- Has no residual effect.
- Only works when coming in direct contact with soft-bodied insects.
- Is biodegradable and nontoxic (if the right soap is used).
- Kills target insects without harming birds or hard-bodied beneficial insects such as predatory wasps, lacewings, and pollinating bees.
How to Apply Insecticidal Soap to Plants
Follow these tips when applying insecticidal soap to plants:
- Repeat Treatment: Insect infestations often require a second treatment with insecticidal soap in a week or so, and possibly even a third. For severe problems, you may want to apply several days in a row, then follow up a week or two later. Keep in mind that the spray stops working once it dries and completely washes away in rain.
- Control Houseplant Insect Pests Safely with Insecticidal Soap (Iowa State)
- How to Make Homemade Insecticidal Soap for Plants (article)
- Ortho EcoSense Brand Insecticidal Soap (scotts.com)
- Organic Pest Control (video)
- Organic Gardening 101 (article)
- Is Pyrethrum a Safe Organic Pesticide? (article)
- How to Use Neem Oil in Your Garden (article)