Zinnia seeds will remain viable for 5-6 years if stored properly. So be sure they are fully dried out before storing.
Zinnias are among the quickest and easiest flowers from which you can harvest and save seeds. And they produce many seeds per plant, so you shouldn't have to purchase seeds or nursery plants if you want to continue growing zinnias.
Plant the seeds only about ΒΌ-inch deep. You'll see seedlings sprout in four to seven days. Once the seedlings reach about three inches tall, thin them so that they're 6 to 18 inches apart to maximize air circulation, a key to keeping zinnias looking good all season.
Planting: Plant zinnias in spring after all danger of frost has passed, around the same time you'd plant tomatoes. Zinnias are easy to grow directly-seeded into the garden. For sooner blooms, start seeds indoors 4 to 6 weeks before your last frost date.. . . . .364011234680!]0000000000000009783314146760!]