monica, just let the best blooms from the best plants dry on the plant; cut off bloom head; let it dry thoroughly inside. The gently pull out the petals, you will see the zinnia seed and the tip of the petal next to the head. Place seed in airtight container and store in a cool, dark place for next year.

This is the way to save all annual flower seeds.

Be sure to label the container with the date, color, plant, etc.

Good luck.

Please keep in mind, however, that the progeny of hybridized seed may very well take on their own personalities. Also, some desireable traits such as disease resistance, heat tolerance, and the like, may not carry over quite as strongly to subsequent generations.

You might take into account the cross pollination that has been occuring in your own garden! Those bad, bad zinnias. :-O

Anyway, just something to keep in mind if your zinnia crop isn't what you expected next year. (Who knows, it could be better than ever.)

I grew zinnias last year in a crate type box and they did wonderfully. I brought the box into the basement over winter and covered it with plastic to retain moisture. It looked pretty much dead this spring and now after a little watering and setting outside there is lush growth but no buds showing yet. I was surprised to see it growing with more plants in it than last year.

Since it only takes about 6 weeks from seed to bloom, I wouldn't spend time trying to overwinter a zinnia. Any place that sells seeds should have zinnias. Zinnias are right behind sunflowers, as far as being the easiest seeds to save and grow, which is always fun, seeing what you get.