Tithonia rotundifolia is commonly called the Mexican sunflower, it is usually grown from seed as an annual, and thrives in full sun in a well drained soil.
Grown for the masses of orange to red flowers this is a tall growing plant that will reach over 1 metre (3ft) in height, sometimes twice this. The height makes it a good candidate for the back of the garden border.
Foliage is a mid green and flowering period is in summer once the heat kicks in. One of the problems with Tithonia rotundifolia is that the stems are rather weak and easily broken, if you can forgive this you will be rewarded with a colourful flowering plant.
How to Grow Tithonia rotundifolia
Usually grown from seed planted in spring after the danger of frosts has passed.
- Choose a sunny position and a well drained soil.
- A position protected from strong winds is recommended.
- Dig the solver well and add some compost to poor soils.
- Do not add large amounts of extra fertiliser and manure as this tends to encourage extra foliage growth rather than flowers.
- Seed should be planted at around 1 metre (3ft) apart. We plant 3 – 4 seeds in each position and then thin to the strongest plant.
- Seed is only covered lightly, a light sifting of soil will do.
- Seed germination will take around 7 – 14 days.
- We suggest staking the plants to avoid stems bending and breaking.
- Keep the soil moist however not wet and soggy.
Tithonia rotundifolia, ‘Fiesta del Sol’ is a dwarf variety, reaching only around 1 metre.