French MArigolds and White and Black Fly

I know French marigolds are supposed to discourage White Fly, does this work with black fly as well ?

I always plant some in my greenhouse and have never had any trouble with whitefly (except one year when the tagetes didn't germinate and grow very well). Can recommend it - presume it works with blackfly as I haven't seen any of those either.

not too sure... do american marigolds work too?

think the plot will be  sea of nasturtions this year after all the seeds I didnt pick up last year I used tagetes last year  with the toms and they worked well - just need to work out now one that banishes slugs