Thanks, Ken Hi Ken, That's a problem.
Sunflower seed is ready weeks or months before it's time to stock the bird feeder.
If they remain upright, they may cure to the liking of bluejays and other birds before you think they are ready for harvest. If left in the garden, the jays will clean them out in a day. If kept in sacks on the ground or hung from walls that mice can climb, rodents will get them and you'll find little mouse nests full of sunflower seed in the ragpiles, truck air cleaner, the guest beds and all over. Closed in the cellar, the still-mushy back side of the flower head will become moldy and ruin the seeds. Covered, but hanging free in flowing, hot dry fall air is what they need.