How to Make an Insecticide

Overview

You can easily, and cheaply, make your own safe soap spray insecticide. Insects will be repelled by plants treated with insecticidal soap, especially soft-bodied arthropods such as aphids, green flies, mealybugs, plant lice, scale insects, spider mites and white flies. But it won't affect most beneficial insects like bees, lacewings, and ladybugs, and it won't hurt birds or other predators. Castile--a natural, all-vegetable, non-detergent type of soap product--won't expose plants, wildlife and the environment to the damaging effects of detergents. So, you'll kill pests without damaging the environment.

Step 1

Grate a large bar of castile non-detergent vegetable oil based soap into a large pot.

Step 2

Add 1 gallon of water. Bring to a boil over medium heat, stirring constantly. Reduce the heat and simmer for 10 minutes, stirring constantly.

Step 3

Allow the insecticide to cool to room temperature. Funnel it into a 1-gallon plastic container. Store in a cool, dark location indefinitely.

Step 4

Shake the insecticide concentrate well when you're ready to use it. Combine 1 oz. with 10 oz. of water in a plastic spray bottle.

Step 5

Apply early in the morning, if possible, to give the solution time to dry. Use on garden plants you think are attracting pests. Never apply any liquid to foliage in hot weather--even water--to avoid leaf burn.

Step 6

Repeat weekly and immediately following rainfall.