Sunflowers, several species of which are native to Colorado, are grown as ornamental garden plants, for their edible seeds, and as commercial crops for confection seeds and oil. Sunflowers offer many ecological and economic benefits to commercial agriculture because they demand few inputs, such as water or nitrogen, and do not require the soil to be tilled. These characteristics make sunflowers a good candidate for crop rotations. Recent research has been looking into hybrid sunflowers that would produce fiber for paper and rubber.
There are many types of sunflowers. Most agricultural varieties are hybrids that have been bred for seed size or oil content. The five kinds of sunflowers that are native to Colorado include both perennial and annual varieties and consist of the common sunflower, Maximilian sunflower, Nuttall’s sunflower, prairie sunflower, and bush sunflower. All sunflowers share certain characteristics: they are upright, with deep taproots and hairy stems that can grow from two to ten feet tall. Their leaf shape ranges from oval to triangular, and flowers are located at the end of their branches.
The common sunflower (Helianthus annus) is an annual with many two- to three-inch-wide flowers on branching stems. They are a leafy and fast-growing variety with erect stalks from three to nine feet tall. While these flowers are grown commercially, they are not the same as the large hybrid crops. Common sunflowers are native to dry plains, prairies, meadows, and foothills of the western United States, Canada, and Mexico, but can be successfully cultivated just about anywhere in Northern America.
The Maximilian sunflower (Helianthus maximilianii) can be found growing wild all over the Americas. They produce clumps of flowers three feet wide on ten feet tall stems. This drought-tolerant perennial grows well in Colorado. Nuttall’s sunflower (Helianthus nuttalli) is native to the damp bases of the Colorado foothills. It grows six feet tall and has long leaves. The prairie sunflower (Helianthus petiolaris) is often seen along roadways of the Colorado plains. This bushy plant grows well in sandy soils, producing many flowers roughly two inches wide. Bush sunflowers (Helianthus pumilus) are native to the dry hills of Colorado. Their leaves have a sandpaper-like texture and the flowers range from one to two and a half inches wide.
Nearly 6 million acres of sunflowers were planted in the United States during the late 1970s; that number dropped rapidly during the 1980s before bouncing back in the 1990s. This pattern of boom and bust has been repeated several times over the past twenty years, and acreage of confection sunflowers and especially oilseed sunflowers in Colorado has fluctuated greatly.
In 1996 oilseed sunflowers were planted on 45,000 acres across Colorado. The dramatic increase in acreage during the 1990s is due in part to the efforts of Colorado State University Extension agronomist Ron Meyer, who worked to develop and extend Colorado sunflower production. At their peak in 2000, sunflowers covered up to 300,000 acres in Colorado, but acreage fell to 215,000 by 2005, according to the National Agricultural Statistical Service.
Interest in sunflowers and other oilseed crops was renewed in 2006 thanks to a national initiative to reduce dependence on fossil fuels and create domestic sources for clean energy. However, this did not result in a permanent increase in production. According to the 2013 Colorado Agriculture Statistics publication, the state produced a total of 124.2 million pounds of sunflowers in 2011, but only 55.2 million pounds in 2012. In fall 2015 Colorado dropped from the fourth-largest producer of sunflowers in the United States to the seventh. But after years of planting fewer and fewer acres in sunflowers, Colorado farmers are beginning to see that sunflowers are a practical and lucrative crop.
In 2010 sunflower farmers either did not till at all or used minimum tillage. This is important because no-till practices reduce greenhouse gas emissions of nitrous oxide by 50 percent thanks to soil carbon storage.
Since sunflowers are native to North America, parasitic insects have had centuries to evolve along with the plants. Recent studies have shown that most parasitism rates are higher in native sunflowers than in their cultivated cousins. Increased planting of cultivated varieties has led to an 80 percent reduction in the amount of herbicide used on sunflowers from 1996 to 2008.
Because sunflowers need little water, they can be grown as a dryland crop. Considering that the cost of full flood irrigation is around fifty dollars per acre, crops that can survive on less water make financial as well as ecological sense. Growing sunflowers in dryland agriculture improves diversification, which helps to manage soil moisture and to interrupt cycles of weeds, disease, and parasitism.
Adding sunflowers to commercial crop rotations not only reduces the danger of pest attacks but also enhances the soil. Sunflowers also reduce the need for expensive chemical inputs, and rotations that incorporate sunflowers have been shown to provide good economic returns. Studies have found that a rotation of winter wheat-sunflower-fallow (uncultivated) yields an annual average of between 862 and 1,162 pounds of crops (wheat and sunflowers combined) per acre, with a profit of about $23.50 per acre. That is nearly double the profit of a winter wheat-fallow rotation, which averages $12.99 per acre.
Varieties of oilseed sunflower that have recently come on the market, such as high oleic, are increasingly in demand due to the health benefits of the oil, which is high in omega-3 and vitamin E. As a result, twenty Whole Foods Stores in Colorado have begun to carry high-oleic sunflower oil. According to the National Agricultural Statistics Service, Colorado farmers brought in a total of 52 million pounds of sunflower seed in 2014, 112 percent more than 2013, from 30 percent fewer acres. In 2015 Colorado farmers expanded their sunflower fields by 20 percent for both confection and oilseed crops, committing 45,000 acres to oilseed and 12,000 acres to confection sunflowers.