How can I control aphids?
Answer: Aphids overwinter as eggs and emerge in the spring, and continue to reproduce all season. They reach maturity in about 10 days, which makes for several generations each growing season. Because of their rapid life cycle, they are hard to control with insecticides. Several species of predatory insects will feed on aphids including ladybugs, green lacewings, and parasitic wasps.
Using insecticides will harm the good insects along with the bad, so spraying all season is seldom beneficial or economical. However, if you have an infestation and want to spray, I recommend a least-toxic pesticide, such as insecticidal soap, horticultural oil, pyrethrins, or neem oil. A good source of information for least-toxic and organic approved pesticides can be found in ATTRA’s Biorationals: Ecological Pest Management Database.
In his publication Aphids—Botanical Control Formulations, NCAT Agriculture Specialist Justin Duncan offers several botanical solutions to manage aphids, including garlic, papaya leaves, rosemary, and mint.
Finally, be sure to check out the Pest Management section of ATTRA’s website, where you’ll find many additional related resources.