Sunflower Culture: Annual. Germination: 14 days, 10 degrees F. Full sun. Direct sow in May or June. Space 12-18" apart. Taller varieties may need staking. Early in the growth stage, place a pole at the base of the stalk. As the stem grows, use twine or soft ties to secure it to the stake every 6' or so. History: Some archaeologists believe that Native Americans may have cultivated sunflowers as early as 3000 B.C. Uses: You can leave any remaining seed-heads in the garden for fall and winter visitors. Or you can cut and dry the seed-heads indoors. Throughout the winter months, tie dried heads to trees or to your deck to create feeding stations.