How to Grow Tithonia Plants
Guide to Growing Mexican Sunflower, Tree Marigold, Mexican Tournesol
Tithonia are half hardy annuals that range from 60 cm to 1.2 m in height (2 to 4 feet).
They bloom from summer through to autumn. Their flowers are reminiscent of sunflowers. These flowers may be yellow, orange, or red.
Some common names for Tithonia plants include Mexican Sunflower, and Golden flower of the Incas.
Tithonia by Superfantastic; Creative Commons.
Tithonia rotundifolia by Carl E Lewis; Creative Commons.
Tithonia Growing and Care Guide
Common Names: Mexican Sunflower, Tree Marigold, Mexican Tournesol.
Family: Asteraceae.
Life Cycle: Half hardy annual. Hardy perennial.
Height: 24 to 100 inches (60 to 250 cm).
Native: Central and Northern America.
Growing Region: Zones 3 to 10.
Flower Details: Yellow, red, orange. Ray and disc florets. Sunflower-like.
Foliage: Deltoid. Lobed.
Sow Outside: Surface. Following the last frost in warm areas. Spacing 24 to 40 inches (60 to 100 cm).
Sow Inside: Germination time: one to two weeks. Temperature 70°F (21°C). Seven or eight weeks before expected last frost. Transplant outdoors a couple of weeks after the last frost.
Requirements: Full sunlight. Light soils. Can survive in dry soils. Provide support. Water in dry periods.
How to Grow Mexican Sunflower and other Tithonia Plants in your Garden
When growing Mexican Sunflower and other Tithonia plants, it is best to start them off indoors unless you live in a very warm area.
Start off about 7 or 8 weeks before you expect the last frost of winter / spring.
The Mexican sunflower seeds should be sown on the soil surface, and will take from half to two weeks to germinate at a temperature of about 20 degrees centigrade (68°F).
The young Mexican sunflower seedlings should be transplanted outdoors following the last frost of spring. Use a spacing of around 60 cm apart (2 feet). Tithonia species should be grown in sunny areas of the garden. and prefer a light soil.
Caring for Tithonia
It is quite easy to care for Mexican Sunflowers and other Tithonia plants. They are quite tall so provide them with a stake. As they like hot dry areas, only provide with water during drought.
As Mexican sunflowers are annuals they should be grown from seed. So do not take cuttings or divide the plants for purposes of propagation.
Common Questions
How many members does the Tithonia genus have?
The Tithonia genus, commonly known as Mexican Sunflower, includes about 11 species.
Do members of Tithonia make a good garden or landscaping plant?
Yes, Tithonia species make excellent garden plants, known for their vibrant, daisy-like flowers. They're ideal for sunny borders or butterfly gardens.
Which Tithonia species are most frequently grown by gardeners?
The most commonly grown species is Tithonia rotundifolia, also known as Mexican Sunflower.
Are members of the Tithonia plant genus fragrant?
While not typically known for fragrance, Tithonia is admired for its bright, sunflower-like blooms that attract butterflies.
What is the perfect location to grow Tithonia?
Tithonia thrives in full sun with well-drained soil. It's a great choice for sunny borders or butterfly gardens.
Is Tithonia invasive in the USA, if so in which states?
Presently, Tithonia is not known to be invasive in the USA. Always refer to local regulations for accurate information.
How do I remove Tithonia plants from my garden?
To remove Tithonia, uproot the entire plant including the root system to prevent regrowth.
Summary
Tithonia is a genus of flowering plants in the family Asteraceae. It is native to the American tropics, particularly Central America and Mexico.
Tithonia grows best in full sun with well-drained soil. Seeds should be sown in spring after the last frost. The plants are drought-tolerant and known for their vibrant, sunflower-like blooms which attract butterflies.
I hope that you enjoyed this guide on how to grow Tithonia plants. You may also enjoy the following Gardener's HQ growing guides: How to grow Layia and Aster plants.
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