Tithonia

Tithonia flowers

A vigorous, erect, bushy annual with thick green foliage and bright dahlia like flowers.

Family: Asteraceae (Daisy family)
Botanical Name: Tithonia
Common Names: Mexican sunflower, Mexican marigold

Foliage: Deciduous, long-stalked, dark green heart-shaped leaves.

Flowers: Solitary, large, dahlia-like flowers, up to 2in (5cm) across, on long stems. Brightly coloured, usually in shades of orange and red with a yellow central disc. Delicately fragrant.

Flowering Period: from mid summer until the first frosts.

Soil: Well-drained, moderately fertile soil (sand or loam). Acid, alkaline or neutral pH. Avoid waterlogged conditions.

Conditions: Best in full sun. Grow in a west or south facing aspect, in a sheltered location.

Habit: Bushy.

Type: Half-hardy Annual.

Origin: Mexico

Hardiness: Tender in the UK. Protect from frost.

Planting and Growing Tithonia

Grows best in a rich sandy loam, in a warm, sheltered position. Protect from strong winds. Tithonia need a long warm summer to perform well.

Very frost sensitive, so do not plant outside until all chance of frost has passed.

Can be plant in separate groups or as a solitary specimen. Makes a good temporary, rapid-growing screen. The cut flowers last well in water.

Taking Care of Tithonia

Water regularly during dry weather and water container grown plants daily.

To improve flowering, apply an all-purpose flowering plant food (slightly higher in phosphorus and potassium) every few weeks, or use a slow release form. Do not over fertilize.

Pruning

Deadhead regularly to extend the flowering period.

Pull up and discard plants to the compost heap at the end of the season.

Pests and Diseases

Susceptible to attack by slugs and snails.

Propagating Tithonia

Sow seeds in late March under glass in trays of good seed compost. Lightly cover the seeds and do not exclude light. Maintain a gentle warmth of 20-25°C (70-75°F). The seedlings should be pricked out and potted on once large enough to handle. Harden-off and move to flowering positions, 12 to 24in apart (depending on variety), at the end of May or early June.

In milder regions they can be sown directly into a prepared seedbed, in May. However, they will need a long hot summer to thrive and flower well.

Popular Varieties of Tithonia

Tithonia rotundifolia a vigorous plant with large, orange-red flowers. Height up to 4ft (120cm). Varieties include:

  • 'Arcadian Blend' mix of flowers in gold, orange and yellow. For sale at Thompson & Morgan.
  • 'Gold Finger' popular compact variety with orange flowers. Height to 30in (75cm).
  • 'Torch' orange-red flowers. Height up to 4ft (120cm).
  • 'Yellow Torch' yellow flowers. Height up to 4ft (120cm).