Family: Asteraceae
Common Name: Marigold

There are two types of marigold commonly grown, French and African, both natives of Mexico and Central America. These upright-growing, branching annuals are easy to culti­vate and are grown for their attractive foliage and brightly coloured, orange or yellow flowers, borne singly or in small, terminal clusters. Most flowers have a very strong smell. Both types are suitable for cutting, but the leaves should be removed from the stems to water level before arranging in the vase.

Species

T. erecta, African marigold, has a stiff, upright habit and toothed, feathery leaves. Flowers have been bred in a range of forms, from double or ball types to more open semi-doubles with looser, more open flower heads of pale to deep golden yellow and various shades of orange. Plants may bloom from late spring until early autumn if dead-headed regularly. Tall strains grow to 70-100 cm (28-40 in) high, medium to 45-70 cm (18-28 in), and the com­pact dwarf forms to 30-40 cm (12-16 in.

T. patula, French marigold, is similar to the African type, but is lower growing, with a more branching habit. The smaller flowers range from dark red to yellow and bloom in summer and autumn, making them particularly useful as cut flow­ers. Of the many cultivars available with single, double or crested flowers, most are dwarf plants around 15 cm (6 in) tall.

T. tenuifolia, signet marigold, is also used for summer bedding, but is not as popular as the other two types. There are many cultivars, all dwarf, bushy plants with masses of small, single flowers in yellow or orange, from the end of spring to tall.

Cultivation

Marigolds are grown as summer bedding plants and, in frost-prone climates, are raised from seed sown under glass in early to mid-spring, and germinated at 21°C (70°F). The young plants are planted out when frosts are over. In areas free from frost, sow in flowering positions in mid to late spring. Marigolds need a position in full sun, with reasonably fertile, well-drained soil. Plants should have dead flow­ers removed regularly to encourage a long period of flowering. If the weather is dry, water well and regularly.

Climate

Warmest parts of zone 9, although grown as summer annuals in all climatic zones.