Growing Sunflowers


Sunflowers have an almost magical name. The word in Spanish is girasol, which translates to “a trip around the sun,” or mirasol, “looks at the sun.” With that in mind, what’s not to love about Helianthus annuus?! H. annuus is a member of the Asteraceae or daisy family, along with marigolds, asters, and the dandelion.

There are 150 species of sunflower—many are native to North America. Sunflowers can be annuals or perennials and have rough sandpapery leaves and showy flowers in a variety of colors. It’s not unusual to see sunflower varieties that vary in height from two- or three-feet up to 20-feet.

The annual has it all—beauty, strength and nutrition. Sunflowers provide a colorful display and a food source for both people and animals. The seeds make a great-tasting butter (much like peanut butter) and around the world the oil is used in cooking.

The sunflower seed is a fruit formed on what appears to be a huge flower. The head of a sunflower is composed of a mass of hundreds of tiny flowers, called florets, all growing individually. The yellow petals that surround the flower head are, in fact, protective leaves that cover the center of the florets.

Did you know that many members of the daisy family including sunflowers are heliotropic, which means blossoms turn to follow the sun when they’re growing and developing? Once a flower reaches maturity, it settles into a comfortable east-facing position and stays there until it dies.

Two basic types of sunflowers are typically grown: oil seed sunflowers and confection sunflowers (for human consumption). Around the globe, many countries grow sunflowers as a food crop, including several U.S. states – North and South Dakota, Minnesota, California, Colorado, Kansas, Nebraska, and Texas. This writer wishes Iowa were one of the states growing sunflowers as a food crop.

Usually, sunflowers are easy to grow because they’re not picky about growing conditions. Generally, they prefer moist soil, some species will even tolerate poor drainage. Typically hardy, the seeds planted in Downtown City Gardens, however, failed not once, but twice.

Sunflowers can be propagated from seed or by purchasing seedlings. Sunflowers do well when sowed directly into the garden that allows them plenty of space and time to develop taproots. It’s best to select an area with six to eight hours of sunlight per day and rich, well-draining soil. They should do well in less than ideal conditions but might not grow as big or strong.

Dig a shallow, one-inch trench and place the seeds two to four inches apart for smaller flowers or six to eight inches apart for larger flowers. It’s important to keep seeds moist until germination, which should occur in seven to 10 days. Watering until germination might have been our problem. Though planted in May during the rainy period, the seeds may have gotten too wet and upon replanting, the seeds may have been too dry.

After the first set of true leaves emerge, thin seedlings that are too close together (closer than two inches from neighboring plants).

Did you know that sunflower sprouts are also edible? So instead of tossing the extra seedlings in the compost, moisten them to sprout and toss in a salad.

[Editor’s note: If you have not done so … check out the sunflowers on the back side of the Demonstration Garden at the JC Fairgrounds. They are impressive!]

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