Jill Bell wrote:
So, what is the real solution?
Grow nasturtiums nearby - they're covered in blackfly, but the runner
beans are clean - tho by next week they'll probably be covered too!!!

Oddly, this year my nasturtiums appear unaffected. :-(
And I've never been entirely convinced that nasturtiums work as a
sacrificial plant and don't just bring the damned things in more.