Can anyone tell me the correct time to harvest and the best way to dry and store sunflower seed heads for planting next year?

Good question; I don't know. Hopefully someone will answer! Keep in mind that hybrid seed will not reproduce true to the plant. They usually revert back to the original plant.

I googled sunflowers & there's a site "sunflowerocity" w/lots of info.

Patty

PS-mine come up on their own year after year.