Basil and Blackfly

What is the secret to growing Basil without attracting the infernal blackfly?

OK you can spray them but then that ruins the leaves for culinary use and they devastate the plant - same with chillies and peppers.

I ended up putting my chillies, peppers and basil out on the sunny patio but my Basil doesn;t do well outside.

Any tips please?

A pot of marigolds on the kitchen window sill net to my potted basil and a hanging basket outside the kitchen window with a nasturtium.

I am guessing autumn/early winter sown basil for indoor use does not suffer blackfly as badly as in spring summer as the blackfly are not around.