The sunflower is a very old plant and is thought to have originated in the western plains of North America. Wild sunflower remains have been found in North American archaeological sites dating from as early as 3,000 B.C. Ancestors of our cultivated type have been traced to the Southwest and Missouri-Mississippi River valley areas.
Sunflower seeds for home gardening come in two types, Helianthus and edible seeds. Helianthus are generally smaller sunflowers and are grown mainly for their summer flower displays. They range from dwarfs of 15 inches in height to taller types up to about 4 feet tall.
The edible seed sunflowers will reach heights of at least 6 feet over the summer. You can sow and grow both types of sunflowers in the garden as soon as the soil warms and frost danger has passed. Indoor seed sowing will allow you to get a few weeks start on the overall growth of the plants.
How to Grow Sunflowers
Spade the soil deeply and allow plenty of space for the plants to develop. Remember, they will get tall, so make sure you plant them on the north side of the garden so they won’t shade other crops in the garden. In some cases, the stem may need to be staked to support the heavy, expanding seed head. For the best results with these plants, a booster application of fertilizer is recommended once the sunflower head begins to appear.
A good layer of compost mulch around the developing stems will conserve soil moisture during the dry summer. Harvest the sunflower seeds when those in the center of each head are mature. The back of the head will turn a greenish-yellow to yellow, and the brachts that surround the seed head will turn brown.
Cut the sunflower head with about a foot of stalk attached and hang it in a warm, dry place. A loose netting tied around the head will keep seeds from falling out as they dry. When completely dry, gently run the seeds from the head and store them in airtight containers or sealed bags.
If you want to learn how to grow sunflowers only for bird food, you might let nature take its course and simply allow the mature seed heads to remain in the garden where birds can feed at will during the fall.
Harvest several heads for use during winter when natural food sources diminish. During the winter months, the dried sunflower seeds can keep you and your birds well fed. There is no ideal seed mix for all birds, but over the years, bird lovers have found that the blackstriped sunflower seed is the closest to an ideal all-purpose bird food.
A feeder stocked with black-striped sunflower seed will attract mourning doves, nuthatches, cardinals, grosbeaks, chickadees, and finches, along with jays, grackles, and squirrels.
For years, sunflowers were sold as a snack food, but studies have indicated it is well beyond the junk food class in which it was once placed. Sunflower seeds are high in many minerals, vitamins and essential acids. However, their high oil content does make them rather high in calories derived from a fat source, too.
The significant nutrients in sunflower seeds include protein, thiamine, vitamin E, iron, phosphorus, potassium, calcium, and the essential fatty acids linoleic acid and oleic acid. Their protein content equals that of beef, they are higher in iron than egg yolks and liver, and they are about equal in potassium to raisins, nuts and wheat germ.