Helianthus

( hee - lee - ANTH - uss )

At-A-Glance Information

This genus includes plants commonly known as Sunflowers, and is native to the Americas. Several species in the genus are well-known as both crops and ornamental landscape plants. They can be either annual or perennial plants, and species vary in habit, from upright growers to more shrubby forms. All are fantastic in pollinator and wildlife gardens, and are also commonly planted in mixed beds and borders, along property lines, and in potager or vegetable gardens.

Helianthus Species and Varietals

The genus Helianthus is a member of the plant family Asteraceae, and includes between 82 and 150 species. The genus name is derived from the Greek words ἥλιος (hēlios, meaning sun) and ἄνθος (ánthos, meaning flower). These flowers grow well in USDA hardiness zones 2-11. To find your zone, click here: Zone Map.

Helianthus agrestis (Southeastern Sunflower)
This species is native to Florida and Georgia in the United States, where it prefers to grow in wet marshlands and pine flatwoods. Individual plants reach up to 3 feet tall and produces bright orange-yellow flowers with dark centers. Stems are branched and somewhat hairy. This annual species flowers in late summer to early fall.

Helianthus angustifolius (Narrowleaf Sunflower, Swamp Sunflower, Narrow Leaved Sunflower)
Native to the southern and eastern coastlines of the United States (from Texas through Long Island), these flowering plants are cultivated for their beautiful bright blooms. They are typically found in low, wet areas and are tolerant of bogs and swamps, though they can also handle well-drained, gravelly clay soils. This species is not considered drought tolerant. Plants reach up to 60 inches tall.

Helianthus annuus (Common Sunflower)
This annual species is typically cultivated for its edible oily seeds, which are often consumed as a snack food. Plants have rough, hairy stems and can grow to reach up to 10 feet tall when in bloom. Leaves are broad, coarsely toothed, and green. Flowering heads are orange-yellow to red, but can also be other colors depending on the cultivar grown. This species is considered invasive in Iowa, Alberta (Canada), Israel, and various regions of South America. There are many cultivars that exhibit various forms, sizes, and flower colors, listed and described below:

'American Giant'
To 15 feet tall, with green foliage and large dark yellow flowering heads.

'Arikara'
Produces single and multi-headed orange or yellow flowers to 16 inches across.

'Autumn Beauty'
Plants reach 90 inches tall, and produce flowers in shades of red, orange, and yellow.

'Black Oil'
Great producer of meaty, oily seeds. Flowers are yellow with black centers.

'Chianti Hybrid'
Deep red sunflowers flecked with gold. Plants reach up to 4-5 feet tall; good for cut flower arrangements.

'Claret F1'
Great cut flower variety with velvety chocolate colored petals streaked with amber.

'Dwarf Sunspot'
To 2-3 feet tall with yellow flowers that have orange centers. Flower heads 10-12 inches wide.

'Evening Sun'
To 7-8 feet tall with 5-8 inch wide flowers in warm, velvety reddish-orange hues. Great for cutting gardens and backs of borders.

'Florenza'
This variety produces lateral branches, and flowers up to 5 inches wide; red with light yellow tips.

'Giant Primrose'
These lemon-yellow sunflowers reach 8-12 feet tall.

'Guillick's Variety'
This cultivar reaches up to 7 feet tall and produces semi-double golden yellow flowering heads.

'Incredible'
This dwarf sunflower cultivar reaches just 20 inches tall and produces 10-inch yellow flowers with brown centers.

'Indian Blanket'
Hardy cultivar with a branching habit and bi-colored semi-double blooms.

'Irish Eyes'
Great for containers or garden growing, this variety produces yellow flowers on a 2-3 foot tall plant.

'Italian White'
To 4-5 feet tall with cream to white flowers that have dark chocolate brown centers.

'Lemon Queen'
Full, dense growth to 6-7 feet tall and 3 feet wide. Lemon yellow flowers 2 inches wide.

'Loddon Gold'
Forms clumps of foliage up to 5 feet tall. Double blooms are orange-yellow and resemble Dahlias.

'Miss Melish'
To 6 feet tall with a spreading, erect habit. Flowers are bright yellow.

'Munchkin'
This dwarf variety reaches 2-3 feet tall at maturity, and produces yellow flowers.

'Orange Sun'
To 55 inches tall, these plants produce double orange blooms that are great for cut arrangements.

'Pastiche'
Plants reach up to 5 feet tall and produce flowers in multiple hues of yellow, orange and red.

'Peach Passion'
3-4 inch single blooms on a plant that has a branching habit. To 3-4 feet tall.

'Peredovik'
4-5 feet tall plants produce single yellow flowers.

'Prado Red'
Red outer petals are yellow on their backsides, and plants reach up to 3-4 feet tall.

'Red Sun'
Great cut flower variety; to 72 inches tall with deep red flowers with brown centers.

'Ring of Fire'
5-inch wide flowers with red centers and yellow tips.

'Skyscraper'
Heirloom varietal that is one of the tallest in the species. 12-15 foot tall plants with single bright yellow flowers up to over a foot in diameter.

'Solar Eclipse'
To a bit over 8 feet tall with beautiful bicolored red and yellow flowers.

'Soraya'
Plants reach up to 5 feet tall, and produce semi-double orange daisy flowers with gold overtones.

'Strawberry Blonde'
Single, 6-inch wide pink and light yellow flowers on plants that reach between 5 and 6 feet tall at maturity.

'Sunsation Yellow'
Classic yellow sunflowers on plants that grow well in containers. To 4 feet tall.

'Taiyo'
Plants to 65 inches tall, producing yellow flowers with black centers.

'Tarahumara'
Classic yellow sunflowers with 8-10 inch wide blooms on plants that reach up to 6-9 foot tall plants.

'Titan'
To 14 feet tall at maturity, with yellow flowers that can reach up to 2 feet across.

'Valentine'
Heavily branched plants produce lemon yellow flowers up to 6 inches wide. Plants reach 53 inches tall.

'Velvet Queen'
This varietal reaches 5 feet tall and produces bicolored yellow and orange-red blooms. Great cut flower.

Helianthus anomalus (Western Sunflower, Sand Sunflower)
This rare natural hybrid species is found in the southwestern United States (Arizona, New Mexico, Nevada, and Utah), where it grows in sand dune habitats. They thrive in stressful, nutrient-poor, dry environments and produce bright yellow flowers on branching plants. Individual plants reach up to 1-2 feet tall.

Helianthus argophyllus (Silverleaf Sunflower, Silver-Leaf Sunflower)
This species, native to coastal regions of Texas in the United States, is an annual herbaceous plant with silvery leaves and stems. It has naturalized in Florida and North Carolina in the United States as well as Argentina, Africa and Australia). Flowers are yellow with brown centers. The species prefers sandy habitats near coastlines and is considered invasive in Florida and North Carolina in the United States, Australia, China, and Mozambique.

Helianthus bolanderi (Bolander's Sunflower, Serpentine Sunflower)
This annual species is native to California and Oregon, and grows mainly in mountainous areas, often in serpentine soils. This wild sunflower species has an erect habit and reaches over 40 inches tall when mature. Flowers have yellow to dark purple or reddish disc florets.

Helianthus californicus (California Sunflower)
This species of sunflower is native to the state of California in the United States and Baja California, Mexico. It grows in many different habitats, and produces 3-10 feet tall plants with yellow daisy-form blooms with sometimes curled disc florets.

Helianthus ciliaris (Texas Blueweed, Yerba Parda, Yerba Parada)
This species is native to the south-central and southwestern United States and northern Mexico. It has a tendency to be weedy, and is a perennial herbaceous plant that reaches up to 28 inches tall when in bloom. Flowers are yellow, and plants can spread via roots. This species is considered invasive in Washington, California, Arkansas, and South Carolina in the United States.

Helianthus cusickii (Cusick's Sunflower, Turniproot Sunflower)
This species is native to the western United States (Washington, Oregon, California, Idaho, and Nevada) and grows in mountainous and foothill areas. It forms a fleshy taproot and reaches up to 4 feet tall, producing lemon-yellow flowers.

Helianthus debilis (Cucumber Leaf Sunflower, Beach Sunflower, Weak Sunflower, East Coast Dune Sunflower)
This species of sunflower is native to the Atlantic and Gulf Coastlines of the United States. There are many subspecies that vary somewhat in appearance. Cultivars have been bred to produce yellow, white, red or orange florets. These plants are sprawling, and can be used as groundcover. This species is considered invasive in Australia, Cuba, South Africa, and various regions across Europe and Asia.

Helianthus divaricatus (Rough Sunflower, Woodland Sunflower, Rough Woodland Sunflower)
These plants prefer to grow in dry, open sites and are native to central and eastern North America. Flowers are yellow and bloom from summer through early fall. Stems are rough, and plants reach up to 5 feet tall. This species is considered invasive in the midwestern United States.

Helianthus gracilentus (Slender Sunflower, Chaparral Sunflower)
This species is native to California and Baja California, Mexico. It grows from a thick taproot to form a 60-inch tall plant with green foliage. Flowering stems are thin, and support golden- yellow flower heads in late spring through fall. Stems and foliage are covered in rough hairs.

Helianthus grosseserratus (Sawtooth Sunflower, Thick-Tooth Sunflower)
This species of sunflower is native to the northern Great Plains and the Great Lakes Region in Canada and the United States. It prefers full sun and moist, fertile soils. Leaves are green, and flowers are yellow and about 4 inches wide. Plants reach about 3-7 feet tall. This species is considered invasive in reconstructed prairies and meadows in the midwestern and eastern regions of the United States.

Helianthus x laetiflorus (Cheerful Sunflower, Perennial Sunflower)
Native to Canada, this hybrid species is a natural cross between Helianthus tuberosus and Helianthus pauciflorus. Plants produce yellow flowers in summertime, and produces smooth, green foliage. This hybrid is commonly cultivated and can escape cultivation and become a weed. Varietal 'Lemon Queen' has lighter lemon-yellow flowers. This hybrid is considered invasive in Ontario, Newfoundland, and regions of the eastern United States.

Helianthus maximiliani (Maximilian Sunflower, Maximilian's Sunflower, Michaelmas Daisy)
This species is named after Prince Maximilian of Wied-Neuwied, who first discovered the plants in his North American expeditions. It is native to the Great Plains in central North America, and has naturalized in many areas of the world. It is typically used as a garden ornamental, but has also historically been cultivated for its tuberous root (similar to Jerusalem Artichoke). Yellow flowers are borne along stems.

Helianthus occidentalis (Fewleaf Sunflower, Western Sunflower, Nakedstem Sunflower)
This species is native to the eastern and central United States, and has sparse foliage. It is a perennial plant that reaches up to 5 feet tall, with most of its foliage concentrated towards the base of the plant. Flowers are yellow with orange-yellow centers.

Helianthus porteri (Porter's Sunflower, Stone Mountain Daisy)
This species is native to the southeastern areas of the United States and is considered a weed in some areas. It is an annual, and reaches up to 40 inches tall in its year of life, producing up to 5 or more flower heads with yellow disc florets. This species is considered invasive in North Carolina.

Helianthus radula (Rayless Sunflower, Pineland Sunflower, Stiff Sunflower)
This interesting species of sunflower produces blooms without any disc florets (or sparse florets), and is native to an area that spans from eastern Louisiana through South Carolina. These plants grow in sandy, open woodland areas like Pine barrens, and reach about 40 inches tall when mature.

Helianthus salicifolius (Willowleaf Sunflower, Willow-Leaved Sunflower)
These perennial plants produce beautiful delicate foliage reminiscent of that of Willow trees (hence the specific epithet salicifolius). The species is native to the central United States, where it prefers to grow in limestone prairies and spreads via underground rhizome roots. One plant typically produces between 6 and 15 flower heads with yellow disc florets. Individual plants reach up to 8 feet tall.

Helianthus strumosus (Pale-Leaf Woodland Sunflower, Roughleaf Sunflower)
This species is native to the Great Plains area of North America, and is a perennial. It grows well in poor or disturbed soils, often densely populating roadsides and fields quite quickly. Foliage is thick and narrow, and flowers are yellow with yellow centers. Roots and seed are cultivated for consumption in some cases. This species is considered invasive in restored wetlands and prairies in the midwestern United States.

Helianthus tuberosus (Earth Apple, Topinambur, Sunchoke, Jerusalem Artichoke, Sunroot, Wild Sunflower)
These plants are cultivated mainly for their edible roots, which are referred to in cooking as Jerusalem Artichoke or Sunchoke. It reaches between 4 and 10 feet tall when mature and in flower, and briefly fragrant flowers that smell of vanilla open in spring and summertime. Blooms are yellow. This species is highly invasive in Europe, Asia, and most of North America.

Caring for Helianthus

Helianthus, or Sunflower, plants can be either grown from seed or purchased as starts or specimens from a reputable nursery. Seeds can be direct-sown in the garden as soon as soil temperatures warm to over 50 degrees Fahrenheit. Plant seeds about half an inch deep, spacing them about 2-3 feet apart for best coverage and airflow. They should be planted in an area that receives full sun, and ensure that it is a protected space that will not be subjected to high winds, which can damage foliage and flowers. These flowers can grow in almost any type of soil, and commonly escape from garden cultivation, taking over disturbed areas of land like agricultural fields and roadsides. Ensure that soil is well-draining and contains a good amount of organic material. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Install a thick (1-2 inch) layer of organic mulch around the planting area to suppress weed growth, maintain soil temperatures, and increase soil moisture retention. Ensure that mulch stays a few inches away from stems and foliage to discourage fungal issues.

Water newly planted Sunflowers regularly to help it develop a strong root system. At maturity, they are considered tolerant of drought conditions, but do better if provided with somewhat regular irrigations. Flowering will lessen during times of drought. As a general rule of thumb, provide water when the top inch or two of soil is dry to the touch. If sunflowers are droopy, it is often a sign that they are being underwatered. Fertilize yearly in early springtime with a application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. At the end of the growing season in fall, flowers can either be cut back to maintain tidiness and discourage re-seeding, or they can be left in place as a food source for local wildlife and to provide rustic beauty to the garden. Annual species will need to be re-sown each year, and perennial species can survive for between 3 and 10 years in the garden before needing to be replaced.

Harvesting Helianthus
Helianthus, or Sunflowers, are a classic cut flower. They have long, strong stems and massive flowering heads, and are in bloom in summer and fall (between July and September). They combine well with many different types of flowers in fresh arrangements. Harvest flowers when the ray florets are just beginning to lift and unfurl from the center disc but before they are fully opened. The best time to harvest is in the early morning or late evening when temperatures are at their coolest. Cut flower stems at their base using sharp, clean shears or snips, remove the lower leaves from the stem, and drop them in a bucket of cool water. The vase life of Sunflower fresh cut flowers is 6 to 14 days.

Sunflower plants can be harvested for either their seeds (which are edible once the hull is removed) or their roots (in certain species). The most popular cultivars to grow for seed production are 'Mammoth' or 'Giant Russian', and the best species to grow for root cultivation is Helianthus tuberosus, or the Jerusalem Artichoke. Sunflowers produce a bountiful harvest of seeds in late summertime, which are ideal for snacking or using as bird feed. To prevent wildlife from snacking on sunflower seeds, place bird netting around the tops of flowers when they begin producing seeds. After harvesting, Sunflower seeds can be stored in an airtight container in a pantry or refrigerator, where they will stay for approximately 2 to 3 months.

Jerusalem Artichoke, or Sunchoke, refers to the harvested roots of the Helianthus tuberosus plant. These flowers have been cultivated for their edible roots for centuries, and are typically ready for harvest 4-5 months after sowing seeds. The tubers themselves are typically beige, but cultivars produce tubers in colors like dark purple, pink, or white. They can be shaped like small onions, or resemble stubby cucumbers. Some even resemble other root vegetables, such as Ginger. Typical yield from a single plant is about 6 pounds of tubers. It is recommended that flowers be taken off of the plants that have been marked for cultivation, as this will mean that tubers do not send any of their energy towards flower production. The best time to harvest Jerusalem Artichokes is between the end of October and November. Simply dig the soil around the plant with a spade and lift the plant with its tubers in one motion. Then, rinse them and remove all dirt and debris. Handle tubers with care, as they bruise easily. Raw tubers can be stored in the vegetable drawer in the refrigerator wrapped in paper towels to absorb humidity, and sealed in a plastic bag or other container. They can be stored this way for between 1 and 3 weeks' time. Canning and freezing are not recommended, as tubers tend to develop discoloration and texture issues.

Disclaimer: Information contained on this website is strictly and categorically intended as a reference to be used in conjunction with experts in your area. Foraging and consumption of plant parts should never begin without the guidance and approval of a local plant specialist. The providers of this website accept no liability for the use or misuse of information contained in this website.

Propagation

Helianthus, or Sunflower, can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Sunflower, follow the instructions below:

Propagating Helianthus by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) peat moss and horticultural-grade sand or grit sand.
In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new flower.

Propagating Helianthus by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed heads are pretty easy to spot, they're left behind after flowers have faded at the tops of plants. Cut the flowers off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will continue to release seeds. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-10 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Sunflower seed heads are quite large, holding up to between 1,000 and 2,000 seeds.

Sunflower seeds have a recognizable striped hull.

Problems and Pests

Certain Helianthus species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Another issue that some gardeners encounter when growing Sunflowers is that the seeds (which have allelopathic properties) dropped on the ground have the ability to kill grasses and other plants underneath. Take care when planting these flowers to locate them away from other prized ornamentals and grasses. Sunflower plants can have issues with the following pests and diseases in the landscape: