Just found this from a vegan website:-
pot marigold flowers are often used in herbal remedies and in cosmetic products. In addition, the flowers can be eaten raw in salads, or used to colour rice dishes. Slugs like to eat the leaves, so you may need to protect young plants from attack.
http://www.btinternet.com/~bury_rd/spgfour.htmEdible Uses
Edible Uses: Colouring; Condiment; Drink.
The flowers are used in refreshing drinks[177, 183]. The leaves are used as a food flavouring[183, 238]. No further details are given. The essential oil is used as a food flavouring, though it is inferior to the oil obtained from T. minuta[238]. The dried flowers are an adulterant of saffron(Crocus sativus), used for colouring foods yellow[183, 238].
Medicinal Uses
Aromatic; Digestive; Diuretic; Sedative.
The whole herb is aromatic, digestive, diuretic and sedative[238]. It is used internally in the treatment of indigestion, colic, severe constipation[238], coughs and dysentery[218]. Externally, it is used to treat sore eyes and rheumatism[238]. The leaves are harvested as required for immediate use during the growing season, whilst the flowering plant can be dried and stored for later use[238].
Other Uses
Dye; Essential; Insecticide; Repellent.
Secretions from the roots of growing plants have an insecticidal effect on the soil, effective against nematodes and to some extent against keeled slugs[18, 20, 200, 218]. These secretions are produced about 3 - 4 months after sowing[200]. The whole plant is harvested when in flower and distilled for its essential oil[218, 238].The oil is used in perfumery, it is blended with sandalwood oil to produce 'attar genda' perfume[238]. About 35 kilos of oil can be extracted from 1 hectare of the plant (yielding 2,500 kilos of flowers and 25,000 kilos of herbage)[218]. The whole plant contains substances that are toxic to cockroaches[218]. The growing plant repels whitefly and can be grown near tomatoes to keep that crop free of the insect[18, 20]. A yellow dye is obtained from the flowers[169]. It is used to colour foods and textiles[238]. The flowers are sometimes used as an adulterant of saffron (obtained from Crocus sativus)[238].
http://www.pfaf.org/database/plants.php?Tagetes+patulaSo based on above i am still somewhat confused. But i know i'm think. So it can be used for flavouring but apparently its bitter.
P.S Sorry gobs i posted just after you, thanks the name thats great i'll go out tomorrow and buy some, cheers catarama! you both deserve a big hug from me!