The Mexican Sunflower, Bolivian sunflower, tree marigold, or the Tithonia plant are considered annual flowers, native to both Central America and Mexico, where varieties of the ponytail plant and spineless yucca trees also call home.
Locals refer to it as the “Golden Flower of the Incas” due to its large, showy bursts of daisy-like flowers.
The name “Tithonia,” pronounced [Tith-oh-nee-uh] for the genus, came from Greek mythology by a French botanist in 1799. Tithonus was loved by the dawn-goddess Aurora.
Mexican Sunflower Tithonia Plant Facts
- Origin: Mexico and Central America
- Family: Asteraceae
- Botanical Name: Tithonia [Tith-oh-nee-uh]
- Common Name: Mexican sunflower, Japanese sunflower, or Nitobe chrysanthemum
- Plant Type: annual plant makes good cut flowers
- Size: 3′ – 6′ feet
- Flowers: bright orange, red or yellow
- Bloom: summer until the first frost
- Hardiness: USDA hardiness zone 3 -11
- Exposure: Full sun or part shade
- Soil: good, well-drained soil
- Water: Average water needs
- Fertilizer: all-purpose fertilizer
- Propagation: seed
- Pests & Problems: no serious pest problems, deer resistant
The Mexican sunflower plant grows to a range of anywhere from 3′ feet up to more than 5′ feet tall in height.
A dwarf selection, ‘Fiesta del Sol’ grows about 30″ inches tall and is great for small gardens.
It’s characterized by bright, flashy orange, red, and yellow flowers showing off their bright hues.
Moreover, the flowers look great as it appears in contrast with their dark green leaves.
Butterflies love to fly around and pollinate Mexican sunflowers. This makes it a good addition to a flower garden if you want it to be visited frequently by butterflies and hummingbirds.
The bright flowers of the Mexican sunflower are a butterfly magnet and a favorite of the Monarch butterfly.
Other varieties of butterflies that see its nectar as a treat include the eastern tiger swallowtail and pipevine swallowtail.
The Mexican Sunflower (Tithonia diversifolia) proves to be a stunner, especially for those who favor sunflowers.
Much like its namesake, the Tithonia diversifolia makes an invaluable, colorful addition to your garden beds and is easy to grow. Here are some ways to grow your Tithonia torch plant beautifully.
NOTE: Another species, Tithonia rotundifolia (red sunflower), is similar in size and growth habitats. The flowers are similar in shape, slightly smaller, and red or bright orange flowers.
How To Grow The Mexican Sunflower Tree Plant
The Mexican Sunflower loves full sun and doesn’t like cold weather. Plant Tithonia rotundiflora, where they receive generous sun all throughout the day. The USDA hardiness zone for growing is 3 – 10.
Adequate soil should suffice in caring for the Tithonia plants; keep a well-draining soil to remove excess moisture.
However, Mexican sunflowers also do well in poor soils and rich soil with plenty of organic matter. These soil types will make your perennial plant flop.
Before planting, put in a good amount of compost for your Mexican Sunflower to grow healthy and strong.
Mexican sunflower plants are drought tolerant, making them great summer plants. Mix in a general-purpose fertilizer as plants grow to promote a healthy surge.
Make sure to plant your Mexican sunflower when all danger of frost has passed, which is usually in mid-spring to late spring.
When watering, ensure not to overwater the plant, as it doesn’t like wet soils. However, provide constant watering in hot summer climates without sufficient rainfall.
Moreover, provide at least 6 to 8 hours of sunlight daily to establish the plant. Once established, The Mexican sunflower will become very drought tolerant.
Remember, this plant needs the proper sunlight and high temperatures to grow and thrive.
The plant starts blooming 2″ to 3″ inches of beautiful flowers from late summer to fall season.
Carefully removing spent Mexican sunflower blooms deadheading to make room for the new ones will encourage the plants to grow flowers for a longer time, even producing bright blooms even in late fall.
For the best results, place Mexican flower plants at the back border and in groups. They can reach anywhere from 3′ to 5′ feet in height and 3′ to 4′ feet wide upon maturity.
Stake plants for straight growth and to prevent them from falling over. When planting in containers, prepare large pots for optimal growth conditions.
Tithonia makes good cut flowers, but handle cut flowers gently as the flower stalks are hollow and brittle.
You can see the Mexican Sunflowers get lots of activity in the video below!
Tithonia “Torch” A Brief History
When new to the world of garden flowers we find new discoveries all the time. Tithonia may be new to many, but the “Mexican sunflower plant” has a history since the naming of the Tithonia genus in 1799.
For example, the plant known as Tithonia “Torch,” which is still available today, was “new” to the plant world in 1951.
- The plant graced the cover of the January 1951 edition of Popular Gardening Magazine.
- The Torch was an All-America Silver Medal Winner
- Described as: “Striking, orange-red and easy to grow, Torch is not too tall for the garden and literally enjoys the hot weather.”
- From Harris Seeds 1951 Catalog: “Torch Tithonia produces a multitude of long-stemmed orange-scarlet blooms often 3″ inches across. The plants grow waist-high and start blooming early. As easy to grow as Zinnias; not troubled by insects or diseases. You’ll want this new ornamental flower in your garden.”
The editors shared this about the Mexican Sunflower in 1951:
“Tithonias of the past made tall, weedy plants, and they flowered late, but ‘Torch’ rarely exceeds 4′ feet and will begin to flower in early summer from spring-sown seed.
Torch Tithonia started to bloom by July 12th and grew up to make a 4-foot bushy plant with heavy leaves and brilliant orange flowers measuring 4″ inches across and kept coming until cold weather.”
Tithonia Plant Propagation
Grow Tithonia Mexican sunflowers from seed. At the onset of cold weather, start them indoors. During warmer months, set them outdoors.
Make sure to plant flower seeds in spring to get earlier blooms.
Remember to keep the soil moist until the Mexican sunflower seeds sprout key.
Growing Tithonia From Seed Outside
Start the sowing process once the last frost passes. Soil should reach a temperature of 60° degrees Fahrenheit.
Mark the site well, as the seeds might take a longer time to appear (about 10 to 21 days). Then, scatter the seeds over the prepared soil in your outdoor or butterfly garden.
Cover with shallow soil, about a fourth inch, and space the seeds about 6″ inches apart. The spacing should be around two feet to three feet apart.
Sowing Mexican Sunflower Seed Inside
If the cold is not a problem in your area, start Tithonia flower seeds outside. Otherwise, start them inside about 8 weeks before the last frost.
The Mexican sunflower seeds should be placed shallowly on the soil surface to allow germination. The germination process takes anywhere from 7 to 14 days with an optimal temperature of 70° degrees Fahrenheit.
You may start sowing from March till April in pots, trays, etc., with a propagator or in a warm place for best results.
The young Mexican sunflower seeds should be transferred outdoors after the last frost of spring at a 20″ inch spacing. Find the sunniest spot in your garden and plant your Mexican Sunflower in light soil.