Planting Mexican Sunflower: Learn How To Grow Mexican Sunflower Plant

If you love the look of sunflowers, go ahead and add some Tithonia Mexican sunflower plants to a sunny area in the back of your beds. Planting Mexican sunflower (Tithonia diversifolia) provides large, showy blooms. Learning how to grow Mexican sunflower is a simple and rewarding task for the gardener who wishes for color in the late season garden.

How to Grow Mexican Sunflower

Reaching no more than six feet and often remaining at just 3 to 4 feet tall, growing Mexican sunflowers can fill your wish for sunflowers in the garden. Consider planting Mexican sunflower as a colorful addition to the water-wise garden area. Let your kids help with the planting too, as seeds of the Tithonia Mexican sunflower plants are large and easy to handle.

This annual grows best in a full sun location and easily tolerates heat and drought conditions.

Plant seeds of Mexican sunflower plants in the ground in spring, when danger of frost has passed. Sow directly into moist soil, pressing the seeds in and wait for germination, which normally occurs in 4 to 10 days. Don’t cover the seeds, as they need light for germination.

When planting Mexican sunflower from seeds in spring, plant them in areas where color in late summer will be needed after summer perennials have started to fade. Growing Mexican sunflowers can provide additional color in the garden. The red, yellow and orange blooms are profuse when you perform necessary Mexican sunflower care.

Allow plenty of room when planting, about two feet between plants, and the Tithonia Mexican sunflower plants will normally stay within their boundaries.

Mexican Sunflower Care

Mexican sunflower care is minimal. They don’t require much in the way of water, nor do they need fertilizing.

Deadhead fading blooms for a late summer explosion of color. Little other care is needed for this vigorous flower. However, Mexican sunflower care may include removal of some plants if they spread to an unwanted area, but growing Mexican sunflowers are normally not invasive. Spreading of Tithonia Mexican sunflower plants can come from dropping seeds of existing plants, but often the birds take care of the seeds before they can re-seed.

Learning how to grow Mexican sunflower is easy, and the cheerful blooms can also be used as cut flowers indoors and on the patio.

Tithonia, Mexican Sunflower

Tithonia, along with sunflowers, are the largest, most dramatic annuals for the garden. Some varieties can grow up to 8 feet tall. A native of Mexico and southward, its area of origin is the reason for its common name. Members of the daisy family, they are also related to the sunflower.

Annuals Image Gallery

Advertisement

Description of tithonia: Tithonias have rough, hairy leaves on tall, vigorous plants. Shorter varieties are now available that will stay approximately 4 feet tall. The flowers are single and up to 3 inches in diameter. The color is a deep orange-red, even though there is now a variety with chrome-yellow flowers.

Growing tithonia: Tithonia must have full sun, but it will grow in average soil with good drainage. It is one of the most heat- and drought-resistant plants, growing reasonably well in soils of low fertility. Plant in the garden after all danger of frost has passed. Space plants 21/2 to 3 feet apart. Do not overwater. Protect the plants from high winds and stake them — this is particularly important in late summer and fall when they are tall and top-heavy.

Propagating tithonia: By seed. Seeds may be sown outdoors; for earlier flowering, start them indoors 6 to 8 weeks earlier. Seeds germinate in 7 to 21 days at 70 degrees Fahrenheit.

Uses for tithonia: Its size and coarseness of the foliage dictates planting it at the back of the border. The color is so intense that it only takes a few plants for impact. It is also useful for covering fences and shielding background eyesores in the garden. Tithonias make good cut flowers as long as the hollow stems are seared after cutting and plunged into 100 degrees Fahrenheit water.

Tithonia related varieties: Torch is a medal winner that grows 4 to 6 feet tall, bearing the classic, deep orange-red flowers. Yellow Torch has yellow flowers. Fiesta del Sol is true orange. Goldfinger is a compact orange to 4 feet.

Scientific Name of Tithonia: Tithonia rotundifolia

Want more information? Try these links:

  • Annual Flowers. Discover your favorite annual flowers. We’ve organized them by color, sunlight, soil type, and height to make it easy to plan your garden.
  • Annuals. There’s more to an annuals garden than flowers. Learn about all of the annuals that enhance your garden.
  • Perennial Flowers. Complement your annuals with these delightful perennial flowers. They are also organized by height, soil type, sunlight, and color.

The Mexican Sunflower, Bolivian sunflower, tree marigold or the Tithonia plant are considered an annual flowers, native to both Central America and in 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 for the genus came from Greek mythology by a French botanist in 1799. Tithonus was a loved by the dawn-goddess Aurora.

Tithonia Plant Facts

  • Origin: Mexico and Central America
  • Family: Asteraceae
  • Botanical Name: Tithonia
  • Common Name: Mexican sunflower, Japanese sunflower or Nitobe chrysanthemum
  • Plant Type: annual flower
  • Size: 3′ – 6′ feet
  • Flowers: bright orange, red or yellow
  • Bloom: summer until 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 plant grows to a range of anywhere from 36″ inches up to more than 60″ inches in height.

A dwarf selection ‘Fiesta del Sol’ grows about 30″ inches tall and is great for small gardens.

It’s characterized by flashy bright orange, yellow and red flowers showing off their bright hues.

Moreover, the flowers look great as it appears in contrast with its 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.

Recommended Reading:

  • Best Butterfly Attracting Plants
  • List of Deer Resistant Annuals

The bright flowers of the Mexican sunflower is a butterfly magnet and a favorite of the Monarch butterfly.

Other varieties of butterflies that sees its nectar as a treat include 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 Sunflowers love full sun, and doesn’t like the cold weather. Plant Tithonia rotundiflora where they receive generous sun all throughout the day. The USDA hardiness zone for growing are 3 – 10.

Adequate soil should suffice in caring for the Tithonia plants; keep a well-drained soil to remove excess moisture. 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 it a great summer plant. Mix in a general-purpose fertilizer as plants grow to promote a healthy surge.

The plant starts blooming 2″ to 3″ inches of beautiful flowers from late summer to fall season.

Carefully remove 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 the Tithonia plants at the back border, and in groups. They can reach anywhere from 36″ to 60″ inches tall 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.
  • 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 flower in your garden.”

The editors shared 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.”

Related Reading:

  • Tips On Growing Mexican Zinnia Plants
  • Tips on Growing the Marigold Flower

Tithonia Plant Propagation

Grow Tithonia Mexican sunflowers from seed. At the onset of cold weather, start them indoors. During warmer months, set them outdoors. Remember keeping the soil moist until the Mexican sunflower seeds sprout is 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). 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 Seed Inside

If cold is not a problem in your area, start Tithonia seeds outside. Otherwise, start them inside about 8 weeks before the last frost.

The 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.

Tithonia diversifolia

Mexican Sunflower

Tithonia diversifolia (Hemsl.) A. Gray is an impressive member of the sunflower family, Asteraceae. Tithonia was named for Tithonus, a legendary Trojan loved by the dawn goddess Eos, who turned him into a grasshopper. Tithonia diversifolia is a perennial native of Mexico and Central America and is cultivated for its beautiful flowers and enormous size. The plant’s flowers are a favorite of bees and African farmers have many uses for the plant, the most popular use being as an organic fertilizer for vegetable crops in either compost or a tea form.

Mexican Sunflower, Click to Enlarge Image

Mexican Sunflower Flowers, Click to Enlarge Image

Mexican Sunflower Leaves, Click to Enlarge Image

Mexican Sunflower Seedhead, Click to Enlarge Image

Plant Facts:

Common Name: Mexican Sunflower

Botanical Name: Tithonia diversifolia

Family: Asteraceae

Plant Type: Large, perennial, rangy shrub

Origin: Mexico and Central America

Zones: 8 – 11

Height: Height and width to 12′ or more

Rate of Growth: Fast

Salt Tolerance: Medium

Soil Requirements: Average, well-drained soil

Water Requirements: Requires regular watering in dry weather

Nutritional Requirements: Balanced liquid fertilizer monthly

Light Requirements: Full sun for best growth and flowering

Form: Shrub

Leaves: Palm shaped, medium green to 6″ wide

Flowers: Yellow, daisy-like, smell of honey — loved by bees and butterflies

Fruits: Gray, flattened, dry, one-seeded fruit hidden by papery, brown-tipped bracts

Pests or diseases: Young foliage attacked by snails and slugs

Uses: Screening, specimen plant

Bad Habits: Foliage damaged by frost, but recovers rapidly

Cost: $$ — Very reasonable

Propagation: Sow seeds in place

Source: A-Z Encyclopedia of Garden Plants, Flora: A Gardener’s Encyclopedia

Tithonia, Sundance

  • Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their seeds from germinating.
  • Mulches also help retain soil moisture and maintain even soil temperatures. For annuals an organic mulch of shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
  • Plants need about 1 inch of rain per week during the growing season. Use a rain gauge to check to see if you need to add water. It’s best to water with a drip or trickle system that delivers water at low pressure at the soil level. If you water with overhead sprinklers, water early in the day so the foliage has time to dry off before evening, to minimize disease problems. Keep the soil moist but not saturated.
  • Until plants become established, some protection from extreme winds and direct, hot sunlight may be necessary. Good air movement is also important.
  • After new growth appears, a light fertilizer may be applied. Keep granular fertilizers away from the plant crown and foliage to avoid burn injury. Use low rates of a slow release fertilizer, as higher rates may encourage root rots.
  • Remove spent flower heads to keep plants flowering until fall.
  • Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
  • Remove plants after they are killed by frost in fall to avoid disease issues the following year.

Mexican sunflower, Tithonia rotundifolia, is a tall plant.

The genus Tithonia in the daisy family (Asteraceae) includes 10-15 species of bushy annuals, perennials and shrubs native to Mexico and Central America that have large, brightly colored daisy-like flowers on thick stems. Mexican sunflower, T. rotundifolia, is a vigorous, drought tolerant warm season annual that is easy to grow in the ornamental garden with other common names of red sunflower of just tithonia.

Tithonia plants grow 4-6+ feet tall, with a large central stalk and a somewhat gangly branching habit. The stems can be brittle. The dark green leaves are ovate to deltoid (triangular) in shape, with serrate to crenate margins. The coarse leaves are usually entire but occasionally will be three lobed. The foliage and stems are covered with a soft downy fuzz, and the underside of the leaves are hairy.

The foliage of Mexican sunflower is coarse and hairy (L); the ovoid to deltoid leaves have serrate margins and are usually entire (C) but may be three lobed (R).

Flowers are produced from mid-summer until frost. The solitary flowers are borne on fragile hollow peduncles (flower stems) that are susceptible to being bent and are often broken by birds. Each 3-inch blossom has a number of bright red to orange ray flowers surrounding the central yellow disk flowers.

Thick, fuzzy buds (L) open (LC) to reveal bright red to orange ray flowers (C) surrounding yellow disk flowers (RC) that remain for a while after the ray flowers fall off (R).

Tithonia seeds.

The flowers are attractive to a wide variety of bees, butterflies and hummingbirds, and can be used as cut flowers. Deadheading spent flowers will prolong blooming. The flowers are followed by grey to black flattened triangular seeds that are easy to collect to save to grow in subsequent years.

Many pollinators visit tithonia flowers including (L-R) bumblebee, longhorned bee, another wild bee, syrphid fly, monarch butterfly and tiger swallowtail.

Use tithonia at the back of borders and beds as a backdrop for shorter plants.

Because of its tall stature, rangy habit and coarse texture, this annual is best at the back of borders and beds to form a backdrop for shorter plants. It can be used as a seasonal screen (especially if grown from transplants started early in the season). Use in mixed or annual borders with tall zinnias, coreopsis, and other flowers in hot colors for a high-energy planting, or tone down the brilliant orange-red flowers by combining with purple flowers and larger plants with dark-colored foliage, such as annual ornamental millet or castor bean or in mixed beds with woody plants such as smokebush or ‘Diabolo’ eastern ninebark.

Tithonia does best in full sun in well-drained soil.

Tithonia grows best in full sun in poor to average, well-drained soil. Avoid planting in rich soil or heavy fertilization that with promote excess foliage and weak stems. Pinch back plants to encourage bushier growth and sturdier plants less likely to fall over, but plants often need to be staked to remain upright. Shelter from strong winds if possible. It has few pest problems and is not favored by deer.

Grow tithonia from seed, either planted directly in the garden at the last frost date or started indoors 6-8 weeks before the average last date of frost for earlier blooms. Sow shallowly as as light is required for germination. Plant in the garden about two feet apart to provide support for adjacent plants, or place staked plants 3-4 feet apart. Since the plants tall with brittle stems, try to provide shelter from strong winds, but even in areas that are not windy these plants benefit from staking. It needs warm sunny weather to grow well so may not do much early in the season. In cool summers, late-planted direct-seeded plants may not bloom.

Tithonia ‘Fiesta del Sol’.

Only a few cultivars are generally available:

  • ‘Fiesta del Sol’ – is a shorter cultivar that only grows about 3 feet tall. It was an AAS award winner in 2000.
  • ‘Goldfinger’ – is a short variety (2-2.5 feet tall) better suited to small gardens with orange-gold flowers.
  • ‘Torch’ – is the most commonly offered cultivar, winning an AAS award in 1951.
  • ‘Yellow Torch’ – has apricot yellow-orange flowers.

– Susan Mahr, University of Wisconsin – Madison

newline]

Download Article as PDF

Leave a Reply

Your email address will not be published. Required fields are marked *