Marigolds are a wonder-drug of the companion plant world, invoking the saying “plant them everywhere in your garden”. French marigolds produce a pesticidal chemical from their roots, so strong it lasts years after they are gone. Mexican marigolds do the same, but are so strong they will inhibit the growth of some more tender herbs. (http://en.wikipedia.org/wiki/List_of_companion_plants)
Marigold is native to the Mediterranean and Iran, This sunny little flower – the ‘merrybuds’ of Sharkespeare – was first used in Indian and Arabic cultures, before being ‘discovered’ by the ancient Egyptians and Greeks. The Egyptians valued the marigold as a rejuvenating herb, and the Greeks garnished and flavoured food with its golden petals. The botanical name comes from the Latin ‘calendae’, meaning the first day of the month. (The Complete Book Of Vetables Herbs & Fruit – Matthew Biggs, Jekka McVicar & Bob Flowerdew)
Our tomatoes planted together with Marigold are doing very well indeed.