What Is Insecticidal Soap?
Insecticidal soap is a very safe product for killing many kinds of pest insects inside and outside the home. The primary ingredients in insecticidal soap are potassium fatty acid salts. Because these salts are relatively nontoxic they offer a safe pest control alternative for many plants indoors and out. Although called “soap,” this compound is not the same as household kitchen soap, which is actually a detergent that works very differently and is actually toxic to plants. Insecticidal soap has been specially formulated to kill specific pests and to avoid injuring treated plants and beneficial insects such as green lacewings and ladybugs.
What Insects Does Soap Control?
Insecticidal soap effectively controls many common soft-bodied insect pests, including aphids, mites, and whiteflies. The soap kills by contact. It penetrates the insect's body and disrupts the normal functions of cells and membranes. It kills both immature and adult stages of insects and mites, but not the eggs. Insecticidal_soap will also control earwigs, mealybugs, leafhoppers, plant bugs, squash bugs, harlequin bugs, and grasshoppers.
Ready Mix vs. Concentrate
Insecticidal soap is available in “ready to use” (RTU) form and in the form of a concentrate that must be mixed with water before use. Generally, the RTU version is appropriate for most yardening situations.
When using the concentrated form be sure to mix the concentrate with water at precisely the ratios indicated on the instructions on the label. The effectiveness of the insecticide is not increased by increasing the ratio of concentrate in the mix. Too much concentrate in a mix can harm the plants however.
Don’t Use Hard Water With Concentrate -The potassium fatty acids in insecticidal soap are inactivated by minerals in “hard” water, such as calcium, iron and magnesium. For best results when using the concentrate form of product, mix the soap in soft water, with less than 17 grains of hardness. It’s easy to test your water. Mix a little soap with water, shake it, and let stand for a little while. If the water is murky with scum on the surface, the water is too hard. Soft water forms a clear liquid with lots of suds.
Don’t Mix With Other Chemicals - Do not mix insecticidal soap with concentrated mineral elements such as lime sulfur, Bordeaux mixture, or copper sulfate. While it is possible to mix insecticidal soap with many other pesticides and fungicides, we advise against this unless you have special training in handling pesticides.