Plant of the Month: Sunflower

Author: Sarah Lineberger

Who can look at a sunflower without cracking a smile? This cheery flower resembles its namesake with brightly colored flower rays that inspire positive and happy thoughts.

Scientific Name: The Sunflower’s scientific name is Helianthus. Helianthus is derived from two Greek words: helios, meaning "sun," and anthos, meaning "flower," so its common name is a direct translation of its scientific name. Hundreds of varieties of sunflowers are available in a wide array of sizes and colors.

The sunflower is a member of the Asteraceae family. This group of plants has a very distinct characteristic -- what looks like a single blossom is actually an aggregate of two different types: ray and disk flowers. Ray flowers ring the edge of the head and appear to be simple petals, but each petal is actually a single flower -- usually infertile female flowers, so they do not produce seeds. The center of the head is filled with a mixture of dark-colored male and female disk flowers, and these produce seeds. Next time you see a sunflower, inspect the individual flowers closely to observe these details.

Plants can range from 2 feet (dwarf varieties) to 15 feet (large varieties) tall, with most growing between 5 to 7 feet. The tallest sunflower on record was 25 feet!

History and Uses:
The sunflower is native to the North American continent, and was originally cultivated by Native Americans around 3,000 B.C. Sunflower seeds were an important part of their diet: they ground seeds into flour; mixed them into a meal with beans, squash and corn; pressed oil from the seeds; and cracked individual seeds open for the rich kernels. Native Americans also used the seeds to produce a purple dye for cloth, body painting, and decoration; used the seed oil for skin and hair care; and sometimes used the dried plant stalks for building material.

Spanish explorers brought sunflowers to Europe in the 1500’s where they were mainly used as ornamental plants. In the 18th century, the production of sunflower oil for cooking increased significantly. The oil was so popular in Russia that during the 19th Century more than 2 million acres of land were dedicated to production of sunflowers!

Sunflower production for commercial purposes began in the United States during the 1900s. At first the harvest was mainly used for animal feed, and seeds were exported to Europe to help meet their demand for oil. Use of sunflower oil for cooking gained more importance in the United States during the 1970s and 1980s when concern over the cholesterol content of animal-based fats led Americans to substitute vegetable oils for traditional animal-based oils.

Sunflowers are still an important crop today. Large farms in North and South Dakota, Minnesota, Kansas, Colorado, Nebraska, Texas, and California grow plants from two categories: oil seed sunflowers and non-oil seed sunflowers (used for the whole seeds or kernels). Sunflower seeds are recognized as having some important nutrients, including protein, folate, and Vitamin E.

Without a doubt, sunflowers are more than just a pretty face. For more information about the production and uses of the sunflower, visit the National Sunflower Association Web site.

Growing Information:
Sunflowers will grow in a wide range of soil types but prefer well–drained areas. Though it's important for plants to receive adequate water during early development, they produce deep roots, and once established they are fairly tolerant of dry conditions.

Plants grow best in full sun -- they are sunflowers, after all -- and it's best to sow seed directly outdoors after the soil warms in spring. You can start seed inside in individual pots to transplant to the garden. The length of time before the plant produces flowers will vary greatly depending on the variety, ranging from 7 to 12 weeks.

For additional growing information from Ohio State University, click here.

Additional Resources:
The National Sunflower Association offers a free educational coloring book for teachers.