If you live in the Boise area, our dry spell means zinnia seed-saving is easy. Clip off dried flowers. Pull each petal off and you'll see the seed at the end. Snap off petals to save space when storing. You can leave them on, too. I put the seeds in a small paper bag. Be sure to label your seed. The zinnias in the photo are from a State Fair Mix. They generally produce true seed, but it's possible they could have been cross-pollinated with other zinnias. Four seeds heads is plenty for the next season. I'll leave the rest of the seed heads so the birds have food during the winter.