answer:Usually a sunflower seed produces one tall stalk and one flower. If the flower is dead, you might want to harvest the seeds when they are good and dry and save them until next spring. Harvesting tips below. Link doesn’t work so I am flying blind. “Harvest sunflower seeds after the flower begins to die back, and most if not all, of the petals have fallen off. Pull out a seed and open it to see if it is full. Cut off the head, leaving a few inches of stalk. Hang the stalks to dry in a well ventilated area. Do not stack them in a box, as mold can develop during the drying process. As soon as the flowers have dried, extract the seeds by rubbing two flower heads together. They should come off of the flowerhead fairly easily.” Source