Family: Asteraceae
Common Name: Mexican Sunflower

This is a small group of tender annuals, peren­nials and shrubs, native to Mexico and central America. One species is commonly cultivated as an annual, while another, T. diversifolia, is a shrub that has become naturalized in many parts of the tropics.

Species

T. rotundifolia, Mexican sunflower, is a colourful, sturdy annual, growing to 1 m (3 ft) or more. It has slightly hairy leaves and orange-red flowers, for a long period through summer into autumn. There are named cultivars, but few show much improvement on the species. Mexican sunflowers are best grown in massed plantings, so plants can support each other. The flowers cut well for indoor use.

Cultivation

Tithonias will grow in any type of well-drained soil, but they do best in full sun with protection from strong wind. Regular watering is needed for establishment but, once growing, they will tolerate dry periods well. In frost-prone climates, raise the annual species in spring from seed germinated at 18°C (64°F) under glass, and plant out when frosts are over.

In frost-free areas, sow direct in flowering posi­tions, in spring.

Climate

Zone 10.