#6: Diatomaceous Earth
A safe natural insecticide is diatomaceous earth, a white powder derived from diatoms. Sprinkle this powder in the soil to reduce slugs, whiteflies, aphids, and other soft-bodied insects. Another effectual fungicide and insecticide is boric acid, which is soluble in water. Make a dilute solution of boric acid and water, and use it for treating fungus, as well as ants, fleas, ticks, and termites.