I have otherwise healthy runner beans, but have a massive infestation of black fly. I've sprayed with garlic infused soapy water, shop bought stuff (which, I'm not keen on), and even planted marigolds to attract lady birds, but the ants scared them off! HELP!!
Certified GKH Gardening Expert
The following article should be of some help to you: https://www.gardeningknowhow.com/special/organic/natural-home-pesticides-organic-garden-pest-control.htm