Increasing concern over the effect of chemical-based insecticides has led many conscientious gardeners to look for better alternatives. Insecticidal soap is just that: It kills insects by entering their respiratory system and breaking down important tissues in the insect's body. Bacterial additives can also introduce a biological control component to the mix. The soap film left behind can also deter insects and other pests from feeding on the plant. Insecticidal soaps are safe, biodegradable and can be easily produced from products readily available at home improvement stores.

Spray bottles
credit: Jupiterimages/Polka Dot/Getty Images

Making Insecticidal Soap

Step 1

Select a dishwashing liquid that does not contain a degreaser or any anti-bacterial agents.

Step 2

Fill a pump sprayer with distilled water. Add 2 tablespoons of dishwashing liquid for every gallon of water to produce a 1 percent soap solution. Stir the mixture thoroughly.

Step 3

Slowly add the de-foaming agent, stirring the mixture until the bubbles disappear.

Step 4

Add Bacillus thuringiensis to the mixture by following the directions on the container. Mix thoroughly.

Step 5

Keep a written record of the mixture. Increase the amount of dishwashing detergent if insects are unaffected. Decrease the amount if you notice any damage to the plants.