I've planted quite a few sunflowers in the Organic Gardening Test Garden over the past two years. And I'm convinced that the absolute best garden sunflowers are the 4- to 6-foot branching types. Among our favorites are 'Sonja', a perky orange-gold with strong stems and clean prickly foliage, and 'Soraya', slightly larger and later-blooming. One of the first to bloom is 4-foot-tall 'Prado Red', followed by sturdy, long-lasting yellow 'Ikarus'. 'Sunrise' is a big favorite with pollinators (that is, bees, butterflies, and other insects), and 'Ring of Fire' impressed us with its great numbers of comparatively small red-ringed flowers. Clear yellow 'Valentine' is a reliable, and beautiful, 5-footer.
If you favor red, 'Chianti' is "a deeper red than any of the others," states Margaret Thorson of Thousand Flower Farm, in Waldron Island, Washington. It's also pollen-free. Thorson also favors 'Italian White', for its elegant creamy-petaled, dark-centered blooms, and 'Indian Blanket', a festive bicolor. "But sometimes," she notes, "the very nicest ones are those that come up from seed the birds missed the year before."
Tom Heaton, Ph.D., a California plant geneticist, began breeding sunflowers decades ago with the goal of making the stems strong enough so they do not topple in late-summer storms. Heaton's 'American Giant' is a single-stemmed Goliath with huge leaves, a tall beauty of a brute that remained upright through most of last summer in our OG test plot. 'Kong' is the branched version.
For gardeners who can't settle for a single variety, 'Autumn Beauty' blends old-fashioned, branching beauties of all colors in each seed packet. 'Giant Sunflower Mix' is a mix of sky-high types.
Pretty and Pollenless
What has brought cut-flower status to sunflowers is the sterility trait discovered decades ago and used in the breeding of oilseed. It seems that certain sunflowers are naturally pollenless, or male-sterile; that is, unlike most plants, which have both male and female fertile flowers, they possess only female characteristics. Breeders create hybrids by fertilizing a male-sterile plant with pollen from a different variety that produces pollen. The lack of pollen not only makes the breeding of hybrids easily doable; it also makes a flower better suited for cutting. Pollenless sunflowers don't shed yellow dust, they are less apt to be allergenic, and they last longer in a vase. When the flowers are fertilized, Heaton explains, "they develop into seeds from the outside inward. That means the outside flowers are drawing resources from the plant and the petals as they fill in and become seeds." He points out that pollenless flowers have abundant nectar and so are still attractive to bees and butterflies. They will make seeds just like any other sunflower if there are others with pollen nearby, though the seeds will almost certainly yield flowers with different traits, if planted.
Hybridizing has yielded such pollenless varieties as 'Lemon Aura', a lemon-yellow branching beauty. 'Go Bananas' is a mix of yellows. 'Infrared Mix' is an assortment of reds.
Short and Sweet
If your garden is too small for giants, or if you grow in containers, you can plant dwarf sunflower varieties. Some of these dwarf hybrids resemble dahlias, or furry yellow pets, more than they do the typical sunflower. 'Baby Bear', for example, is a fuzzy lovable shorty when freshly blooming. 'Music Box' is a combination of mini-sunflowers.
The mighty midgets have just two drawbacks: The blooms (like those of tall sunflowers) face the ground once they mature, so that you find yourself looking down on the backs of the flowers. And unlike their taller brethren or other tall branching flowers, such as zinnias, the side-branching flowers often don't top the first bloom but stay at a lower height.
Single-stemmed sunflowers are the ultimate in long-stemmed cut flowers. For cutting, plant the 'Sunrich' and 'ProCut' series, suggests Keith Baldwin, Ph.D., horticulture specialist at North Carolina State University. Lynn Byczynski, of Lawrence, Kansas, author of The Flower Farmer and editor of the monthly journal Growing for Market, is captivated by the double-spiral seed pattern in the single-stemmed dwarf 'Zebulon' (named, we suspect, for Monsieur Zebulon, an animated wizard who bounces around on springs).
A 2005 study performed by Japanese scientists reported that when sunflowers were picked just as the petals were unfolding, they lasted more than a week--but less than two-- in a vase. Standouts among the 28 varieties evaluated include 'Munchkin', 'Moonlight', and 'F1 Premier' (all pollenless). For a continuous supply of cut sunflowers, plant seeds every two weeks, advises Baldwin. Consider single-stemmed sunflowers a crop, rather than a garden plant. In our test garden, they provided two weeks of color after 50 to 60 days of green.
The sunflower is one of the few crop species that originated in North America. It traveled with early settlers to Europe, then to Russia, where it was adopted and transformed. After Russian breeders nearly doubled the oil content in the seeds by selection breeding, it was brought back, newly respected, to the United States. Scientists see a bright and shiny future for our native sunflower. The plants are used to filter contaminated water and to extract lead from soil. The seed oil can be used in diesel engines, and now scientists from the University of Leeds have discovered a way to extract hydrogen from the oil, a potential means of powering a hydrogen car!