If you grow sunflowers, you often will find the birds helping themselves to seeds right off the sunflower head before you have a chance to harvest them. Still, it's nice to save the rest of the harvested sunflower seeds to offer your feathered friends during the winter. Harvesting and drying sunflower seeds takes a bit of time, but it is not difficult.
Remove the sunflower heads from the plant stalks only after the petals have dropped and the sunflower head is dry and brown. Cut the flower head from the sunflower stalk, about 2 to 3 inches down from the bottom of the flower. If you cut the flower portion off the plant before it is dry, it will be difficult to remove the seeds later.
Cover each of the flower heads with a paper bag. Scrunch the bag up around the short stalk at the end of the flower. Twist a rubber band around the bag and stalk or tie a string around it. The bag will collect the falling seeds as the sunflower head dries further.
Tie the bagged sunflower heads upside-down onto rafters of a garage or garden shed. The drying location must be a moisture-free, well-ventilated area. After three or four weeks, the flower heads should be completely dry.
Take the bagged flower heads down. Shake them vigorously to remove all of the seeds. Remove the bag and string. Clean out any dried plant debris from the seeds. Store the seeds in airtight containers until it's time to fill the outdoor bird feeders.