Marigolds and calendula for pest control?

[kentishgal]

Nasturtium are a sacrificial plant, attracting blackfly and cabbage white caterpillars. Once they're infested, pull them up and compost the lot, pests an' all.

Nasturtiums are fantastic for attracting blackfly and other bugs. Added bonus is that it spreads so easily so you dont have to plant/sow it new each year, just move any seedlings from where you dont want them...they have come up like weeds in my garden this year (including growing from the compost bin, between paving cracks and out of old flower pots!LOL).
I also put some water in my garden to attract insects to eat the bugs too. Only room for a large plastic trough but it supports some grasses, a water lily and pond weed and had hoverflies and dragonflies hanging around it last year.