Zinnia are annual flowers that produce brightly colored blooms suitable for garden beds or as cut flowers. Ranging from small dwarf varieties to giant zinnia, they bloom from mid-summer until the first frost. Many zinnia self-seed in the garden, but to ensure you have plenty growing next year you must continue to reseed them each spring. Collecting zinnia seed allows you to save money and continue to grow your favorite varieties year after year. Depending on the zinnia type, seeds range from the size of a sesame seed to large seeds the size of a shelled sunflower seed.
Let a flower head bloom and wilt naturally. Wait for the petals to drop off and the cone shaped seed head to mature.
Snap off the stem once the seed head and stem have dried, approximately one to two weeks after blooming. Seeds that are mature are either green or brown in color.
Lay mature seed heads in a single layer. Place in a well ventilated, warm room to finish drying for two weeks.
Break apart the seed head and remove the seeds. Pull large seeds out of the cone and separate as much excess plant material as possible from the smaller seed varieties.
Label an envelope with the type of zinnia and the year harvested. Place the seeds inside envelope, then store in a cool, dry place.