Homemade Control of Plant Scale
Many people prefer to use homemade control of plant scale. Insecticidal soap is a safe and effective alternative to conventional insecticides. You can bleach free dishwashing liquid (1 1/2 teaspoons per one quart of water) in place of commercial insecticide soaps. Homemade control of plant scale can also be achieved with oil spray. Mix two tablespoons of cooking oil and two tablespoons of baby shampoo in one gallon of water. This can also be mixed with one cup of alcohol to help penetrate the insect’s shell.
If a fungus is also present, add two tablespoons of baking soda. Test the spray on a small area of the plant, beforehand and wait 2-3 days, to check for damage. Do not spray plants in the sun or on hairy or waxy-leaved plants. Shake well before and during application. Spray every 5-7 days as needed, covering both sides of the foliage. Wash the leaves individually with the soap/oil mixture and rinse well.