My grandpa swore by Sevin, and my father in law uses diluted Dawn soap. Based solely on the chemical content, I'd start with the soap. Also - predators. You

My grandpa swore by Sevin, and my father in law uses diluted Dawn soap. Based solely on the chemical content, I'd start with the soap. Also - predators. You can buy ladybugs in most garden centers for almost nothing, and they eat aphids for breakfast, lunch, and dinner. Literally.