Large, double, lemon yellow flowers up to 1m tall.
Requires a well-drained moderately fertile soil in a sunny position. Grows well in heavy clay soils and in sandy soils.
Although not very frost resistant, it can be grown as a tender annual in Britain, sowing the seed in a greenhouse in the spring and planting out after the last expected frosts.
Removing dead flowers before the seed is formed will extend the flowering season.
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 flower petals also have nematacidal properties. The growing plant is also said to repel insects and can be grown amongst crops such as potatoes and tomatoes. A yellow dye is obtained from the flowers.
A yellow dye obtained from the flowers can be used as a saffron substitute for colouring and flavouring foods.The plant is used as a condiment. (This probably refers to the use of the flowers as an edible dye).