Hi there - just to confuse even more, some of the marigolds, being Mexican, also appear as French Marigolds. Ah well - use the latin, Tagetes, unless they've changed that one too.
Tagetes (especially the simpler and older varieties, apparently) deter white fly. I read somewhere they also confuse the Cabbage White, and deter carrot fly. So what if they don't, they still add a touch of colour to a brassica bed!
The Tagetes is also apparently supposed to deter nematodes - the vegetarian worms that attack root crops, like potato eelworms. Only works if you sow a whole bed of them, though.
Unfortunately, the "other" marigold, calendula officinalis, is a happy feeding ground for the nematodes. Visions of the calendula bed slowly crawling across the path to devour my potatoes.
All best - Gavin
