Recipes for homemade aphid spray include dish soap diluted in water and insecticidal soap. Additional recipes include neem oil or a combination of herbal essential oils, including peppermint, thyme, clove and rosemary.
To create the diluted dish soap spray, mix 2 tablespoons of dish soap in 1 gallon of water. Place the water in a spray bottle for usage. Spray the mixture on affected plant leaves and directly on aphids as applicable. Carefully rinse away the mixture from the affected plant after one to two hours to avoid damage to leaves. Reapplication may be needed for advanced populations.
Insecticidal soap is available for purchase, and comes with instructions by brand. It is easy to mix at home. It should be noted that use of this soap may inadvertently destroy helpful species that naturally kill aphids.
Neem oil may be used in the same way as diluted dish soap. All procedures are the same, though this oil also repels most other insect species.
To use herbal oils to get rid of aphids, mix 1/4 teaspoon of peppermint, thyme, clove and rosemary essential oils in 1 gallon of water. Shake thoroughly before application on plant leaves. This remedy also serves to repel indoor and outdoor insects, while killing eggs and larvae.