Sunflowers come in many sizes, from towering giants with a fringe of petals around a plate-sized seed head to delicate shrub-like plants with an abundance of daisy sized flowers. Modern horticultural techniques have produced a variety of colors, as well.
Purchase sunflower seeds in seed packets intended to plant. Seeds sold as snacks may not be viable.
Sow these annuals outdoors, after the danger of frost is past. Start them indoors and transplant the seedlings to the garden once frost danger is past.
Larger, single-flower varieties will make visible gains in height daily. Multiple-flowering varieties are less conspicuous, but still grow steadily with suitable conditions.
As the flowers develop they turn throughout the day, following the track of the sun across the sky. The giant varieties display this trait most noticeably.
Harvest sunflower seeds for eating when they appear plump and begin to loosen in the seed head. Many growers wrap the seed head in a light cloth, such as cheesecloth, once the seeds begin to form in order to protect them. Once they have gone to seed, the plants will begin to die.