In the last few years, my wife has added sunflowers (Helianthus annuus) to various locations in our landscaping and vegetable garden as an impromptu filler where we had unused space or an empty spot from something that didn’t make it through the winter. The towering plants adorned with bright yellow, often dinner plate sized, flowers have been a showy and interesting addition. At maturity, the flower heads are filled with seeds that are a favorite among songbirds and other wildlife on our property. From an ornamental standpoint, the interesting addition of extreme height is an added benefit as there are few other plants that can grow as tall as fast as these gigantic annuals.
Sunflowers are members of the aster family (Asteraceae) and are native to North America. These enormous annual plants have a single stem which grows up to 10ft tall in a season, bearing one large seed head at their apex. Each head consists of showy, yellow ray flowers around their periphery with up to 8,000 smaller disk flowers in the center. As the disk flowers mature, they produce and abundance of fruits, referred to as achenes, botanically, but often called seeds by the layman.
The sunflower began its relationship with humankind during the prehistoric era during which it originally inhabited large swaths of western North America. Native Americans collected the seeds of wild sunflowers for food, capitalizing on its bountiful seed heads as they matured in late summer. Beyond food, dried stems were used for construction and fuel, flowers for pigments, and various other plant parts were used medicinally.
Sunflower is believed to have been distributed outside of its home range inadvertently as prehistoric Native Americans moved about carrying the valuable seeds with them to central and eastern North American. Seeds were unintentionally dropped near seasonal campsites and other areas allowing sunflowers to crop up as weeds along human travel ways. It has been hypothesized that Native Americans first proliferated sunflower as an encourage weed before later cultivation for a major food crop as agriculture became a larger part of Native American culture.
Recovery of ancient seeds in archeological remains from eastern North America indicates that sunflower was domesticated sometime before 1500 B.C. and that it was in widespread cultivation by 500 B.C. Other records reveal that it was also cultivated in the American Southwest and Mexico around that same time period.
As sunflower cultivation began, mutations occurred and plant selection drove some change from the ancestral, wild genetics. Prehistoric sunflower plants were likely very similar in overall size to modern sunflowers, although selection for greater sized seeds by Native Americans produced up to 4 times larger seeds during its early domestication.
By the time of any European historical records of sunflowers in North America, maize (corn) was the primary crop among Native Americans. However, sunflower had been one of the major agricultural crops of the Eastern Woodlands of North America for over 700 to 1,000 years prior to the arrival of already-domesticated maize from Mexico and Mesoamerica.
Sometime after 1492, when Columbus and others arrived in the new-world, the sunflower made its way back to Europe, presumed to have debuted on the continent in Spain. The first actual written record of sunflowers in Europe can be found in 1568 with plant reaching widespread cultivation on the continent by the end of the 16th century.
By the early part of the 1800’s Europeans began extracting oil from sunflower seeds for a variety of uses. In the early 20th century, breeding began for earlier-maturing varieties with higher yields. Up to 20-50% increases in oil content of seeds were incorporated into the plant, along with the development of semi-dwarf varieties which could be harvested mechanically, paving the way for very large-scale, global production of sunflower.
Today, a large number of sunflower varieties are available for both agricultural production and ornamental or home garden planting, as my wife has done around our property. They are easily established from seed in late April of early May and provide a wonderful, towering backdrop to vegetable garden beds. I love having a single solitary sunflower or two plunked into a landscape bed for a bit of height diversity where needed. Their uses are many and they create a neat and interesting oddity among other landscape plants that will certainly be a wildlife favorite.
From a historical perspective, sunflowers are perhaps one of temperate North America’s most unique and remarkable contributions to the world’s major food crops, remaining one of the most import oil seed crops even today. Sunflower has even become somewhat of a trend in modern American culture with depictions of sunflowers appearing on everything from t-shirts, coffee mugs, and beach towels to advertising images, along with wild popularity among the baseball following. Who knew that ancient Native Americans could leave such a lasting, global legacy from the ingenuitive use of a native plant?