Sunflowers (Helianthus annuus)

One of the most recognizable garden flowers is the classic annual sunflower (Helianthus annuus). Its flower head consists of a dark disk surrounded by petals that range in color from the traditional yellow to shades of creamy white, orange, and deep red. The flower is supported by a coarse hairy stalk bearing triangular-shaped leaves. The sunflower has been hybridized into many varieties, including those with red, orange and bicolored petals, dwarf and mammoth varieties, and those with double flower heads. Doubles are available to contemporary gardeners as the ‘Teddy Bear' variety.

Benefits of Planting Sunflowers

• Thrifty gardeners should note that growing sunflowers from seed gives great “bang for the buck!”
• Seed packets are readily available for under $2.00 and yield many plants for your flower beds and containers. These are reliable growers, whether directly sown in the soil or started indoors.
• Since sunflowers are annuals, they are good plants to experiment within the garden without the cost, location considerations, or maintenance of perennials. After an exceptionally mild winter, a few sunflowers have been known to re-seed from last year’s crop.
• In maturity, their color and stature are striking additions to the flower garden and home landscape.
• Pollinators love sunflowers! The Xerces Society considers sunflowers to be great plants for pollinators, especially late in the season. Bees find sunflowers useful not only for nectar but also for wax for their hives. Sunflower is a host plant for a number of moth and butterfly species. Be aware that while “pollenless" varieties are useful as cut flowers, they provide no benefit for bees, butterflies, and other hungry pollinators.
• Because the flowers are larger and taller than others, it is easy for the gardener to observe, identify and photograph visitors – pollinators and birds.
• As the flower seed heads mature, it’s great fun to watch the birds perch to eat the tasty seed. Frequent visitors include American goldfinches (Spinus tristis), who hang upside down on the flowerhead as they pick out seeds.
• Sunflowers make great cut flowers to bring inside to enjoy up-close. For this purpose, consider growing pollenless varieties.
• To dry the seeds, cut the entire seed head as the flowers begin to fade. Place it in a paper bag. Place the paper bag in a dry, dark, and warm place to dry. Bring it out on a snowy day and place it in your bird feeding area. Keep your binoculars and bird guide handy, as 45 species of birds are known to eat sunflower seeds.
• Sunflower seeds are also a tasty and nutritious snack for humans.
• The annual sunflower is native to North America. It is believed to have been domesticated from the wild sunflower around 1000 B.C. in what is now the western United States.

Growing Tips

• Full sun is best for growing sunflowers.
• Biodegradable containers, such as peat pots, are great for starting sunflowers indoors four to six weeks before the average last frost for your area. You can plant the seedling, container and all, without disturbing its roots.
• Plant seeds directly in the ground or transplant seedlings after all danger of frost has passed.
• Plant seeds one-inch deep, spacing 6" apart for varieties that mature at two to five feet, one foot apart for varieties that are taller, and two feet apart for giant varieties. Check directions on the seed packet.
• Extend the flowering period by planting seeds in intervals of one to three weeks, or by planting varieties that mature at different times.
• Sunflowers can withstand some drought.
• Water them regularly 20 days before and after flowering to encourage abundant root growth, which is helpful with taller sunflower varieties bearing top-heavy blooms.
• With a good root system, the plants are generally strong and do not require staking. Planted in a windy area, a tomato cage may provide enough support.
• As the plant grows, you can experience a fascinating botanical characteristic. The young sunflower head follows the sun, a quality known as heliotropism or phototropism. As the plant ages, the stem stiffens and this movement ceases. The mature head usually faces east.

Sunflower History 

• Sunflowers were eaten and used medicinally by Native Americans, who shared a dish with Lewis and Clark. Their journal of 1805 records “a very palatable dish" of ground sunflower seed meal, mixed with grease from cooked meat and made into a dough, then eaten.
• Elizabeth Cady Stanton and Susan B. Anthony adopted the Kansas state flower, the sunflower, as a symbol of the suffrage cause.
• The sunflower was a favorite subject of Dutch impressionist Vincent van Gogh. He painted seven versions of sunflowers, depicting typical sun-shaped flower heads as well as the double-flowered variety.

'Teddy Bear' double sunflower variety. Photo credit: Holly List

Fun with Sunflowers 

• As noted, sunflowers are easy to grow, making them a good plant for gardening with children. Check out these plans for a “Sunflower House" planted in a play area of your garden: The Old Farmer's Almanac, How to Grow a Sunflower House.
• Convince your friends and neighbors to have a contest to see who could grow the tallest sunflower. ‘Russian Giant' and ‘Mammoth' can grow upwards of twelve feet tall!

Please be encouraged to explore, expand and enjoy sunflowers in your garden this year!

Sunflower contest winner. Photo credit: Holly List