Mild Detergents to Get Rid of Aphids

Aphids

• Aphids are tiny insects that live off the juices in the tender parts of plants. Although the most familiar aphid to the home gardener is green, there are also red, brown, yellow, white and black aphid species. Some aphids’ bodies are covered with fur or with a waxy substance. Aphids aren’t loners and are easy to identify by the way they cluster together, especially on the undersides of leaves. When disturbed, they remain in place, unlike other insects that may move rapidly or fly away.

How Detergent Kills Aphids

• Scientists are still not quite sure how insecticidal soaps work but assume that they kill aphids in one of two ways. Soaps and detergents may dissolve the insects’ outer covering and disrupt cell function, causing the cells to collapse, or they may block the insects’ breathing holes so they suffocate. With this in mind, it’s important to apply the detergent solution directly onto the aphids until they are covered with it.

Detergents and Soaps

• While commercial insecticidal soap preparations may be safer for your plants, according to Colorado State University Extension entomologist W.H. Cranshaw, some household soaps and detergents are equally as effective. According to a study published by the University of Illinois, Palmolive, Dawn, Joy, Ivory and Dove liquid detergents are effective controls for green peach aphids and cabbage aphids on vegetable crops. The study also found that Tide detergent and Ivory liquid dishwashing soap reduced aphids on ornamental plants. Organic control may be achieved by using organic liquid soaps such as Desert Essence or Dr. Bonner’s.

Considerations

• A 2 percent solution is ideal to manage aphids and can be created by adding 4 teaspoons of mild liquid detergent to a quart of water. Some gardeners add other ingredients to the detergent solution, such as mineral oil, to help the spray remain on the leaves. Since household detergents aren’t manufactured as insecticides there is always a chance that damage to the plant may occur. Leaf burn is a common result of using homemade detergent solutions for aphid infestations.