Sunflower plants make striking additions to any backyard garden, thanks to their tall and stately appearance--some varieties grow 10 feet tall or higher--and giant yellow blossoms. These blossoms produce a profusion of little black seeds. Harvest the seeds for consumption, and save some for replanting in the following growing season, so you can keep raising sunflowers without having to buy new seeds.
Wait for the sunflower blossom's petals to wilt and fall off. Immediately cover the entire blossom head with cheesecloth, securing the cloth in place with garden twine. This prevents squirrels, birds and other animals from eating the sunflower seeds before you harvest them.
Inspect the sunflower head regularly. It's ready for harvesting when the back of the flower head is crisp to the touch and brown in color and when the seeds are black-and-white striped, according to the University of Illinois.
Remove the cheesecloth. Cut off the flower head with pruning shears. Rub your hand over the face of the flower head to dislodge the seeds. Empty the seeds into a paper envelope for storage until you're ready to replant them.
Replant the seeds directly in the ground anytime after the last frost date in your region. Bury a seed 1/2 inch under the soil surface, and water twice daily or as needed to keep the dirt moist. The seed will germinate within 14 days, according to the University of Massachusetts.