Secretions from the roots of growing plants have an insecticidal effect on the soil, effective against nematodes and to some extent against keeled slugs. These secretions are produced about 3 - 4 months after sowing.
The whole plant contains substances that are toxic to cockroaches. The growing plant repels whitefly and can be grown near tomatoes to keep that crop free of the insect.
A yellow dye is obtained from the flowers. It is used to colour foods and textiles.
A very ornamental plant. A good butterfly plant. Removing dead flowers before the seed is formed will extend the flowering season. The bruised leaves emit a refreshing pungent smell.
The French marigold is often used as a companion plant, especially for growing amongst tomatoes and potatoes where it helps to repel pests.
Requires a well-drained moderately fertile soil in a sunny position. Grows well in heavy clay soils and in sandy soils.
The flowers are used in refreshing drinks.
The leaves are used as a food flavouring. 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.
The dried flowers are an adulterant of saffron(Crocus sativus), used for colouring foods yellow.