Texas Agrilife Extension Service
Texas A&M University, College Station, Texas

June, 2008


Sunflowers - Enjoy the Flowers....Give Birds a Treat


by Cynthia W. Mueller
Master Gardener, Galveston County

Sunflowers are an essential part of the summer garden. Besides their decorative qualities, they play an important part in agriculture by the production of seeds for fuel and cooking oil. In the home landscape, they are also important sources of food for wildlife and birds.

Classic
Classic "Seeds of Change" sunflower poster
Garden sunflowers may be found in heights from 15 feet to about 3 feet and are descended in part from the Common Sunflower (H. annuus). There are many, many varieties ranging in color from white through yellow, red, chocolate and often bands of contrasting colors.

Perennial Varieties: There are approximately 50 species of sunflowers native to North America, and 38 of these are perennial species such as Jerusalem artichoke and Maximilian sunflower (Helianthus maximilianus). Others include:

  • Silverleaf Sunflower (H. argophyllus) - Stems and leaves covered with silky gray down, especially on younger growth. Flowers golden with purplish brown center, plants 5 to 6 feet tall. Silvery leaves used in fresh and dried flower arrangements.

  • Cucumberleaf Sunflower (H. debilis) - Four-foot plants with multiple branches, excellent for cutting. The three-inch flowers have a purple disk and yellow rays.

  • ‘Lemon Queen’ is a single form suitable for cutflowers, and the old favorite ‘Flore Pleno’ is fully double and lasts in the garden for many years.

One way to distinguish annual from perennial sunflowers is by examination of the roots. Annuals have the usual stringy roots, but on perennials roots often have thickened into storage tubers.

Ornamental Annual Sunflowers: Garden sunflowers are usually annuals created by the crossing of several species and the range of choices has greatly expanded in the last few years, with the introduction of red coloration, which produced many beautiful new hybrids such as the deep-red ‘Velvet Queen’ or the yellow and red bicolor ‘Joker.’

Some fancy modern sunflower varieties are rather delicate, and the seeds expensive. It’s often a good idea to begin germination of the seeds on moist paper towels, gently rolled up and put out of harm’s way for several days. Or, lay them out on a dampened paper towel on a dish and cover with another moistened towel. Unroll the toweling and inspect seeds daily after the first week or so. Remove vigorously sprouting seeds and replant l/4 inch deep in peat pots that can be buried in the ground intact with the young sunflower plant.

These precautions don’t need to be taken with varieties more similar to “wild” sunflowers, such as ‘Silver and Gold’ which is a hybrid of the wild species H. argophyllus. This treelike annual may reach 12 feet in height, loaded with smaller yellow single blooms. The seeds are slim, but extremely attractive to birds, and the soft, downy leaves are silvery in color. More sturdy varieties may be planted in clusters 1” deep in the garden where they are to remain.

Full sun is important to sunflowers and you can actually observe the flower heads turning through the day to face the source of sunlight. Jerusalem artichokes (Helianthus tuberosus), a form of sunflower with an edible tuber, received their name from the Italian word ‘Girasole’ which means ‘turning to the sun.’ These were an important food crop to native peoples of the Americas. The Japanese have created new strains of sunflowers such as ‘Cinnamon Sun’ and ‘Chocolate Cherry’ lacking the usual pollen, so that they may be used in floral arrangements without the usual messiness of scattered pollen.

Sunflower varieties for seed production include specialized strains bred for enormous heads, such as ‘Russian Mammoth’ or ‘California Greystripe’. The new cultivar ‘Sunzilla’ offered by Renee’s seeds is not only quite tall but has an extra-sturdy stalk as well. Storms or heavy winds often wreak havoc with taller sunflowers. Growing in full sun helps to keep plants compact. These large heads need to be carefully dried after harvest before the seeds are removed to be stored.

Birds with beaks for processing seeds, such as cardinals, finches and sparrows all enjoy these seeds. It’s fun to allow some of the smaller sunflower heads to continue to dangle from the plants so that the birds’ antics while feeding may be watched.

Sunflowers are an ancient food crop. Scientists recently discovered remains of seeds from 300 B.C. and estimate that they have been grown for food for more than 4,600 years in Mexico. Evidently sunflowers were independently domesticated by American Indians in the Mississippi valley. The larger size of the prehistoric seeds show that they were a product of domestication.


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