Seed Harvesting in September

In late summer and early fall, I like to start gathering seeds from vegetables and flowers to plant in the coming year. I continually deadhead flowers in the spring and summer so that new blooms appear.

Deadheading means cutting off faded flowers before they set seed. A plant that isn't making seed keeps putting energy into new blooms, so regular deadheading stretches the flowering season, and it keeps plants looking tidy. Late in the season, stop deadheading the plants you want seed from and let the last flowers ripen.

Seed is ready when the flower head or pod has turned brown and dry on the plant, and the seeds come away easily. Marigolds, zinnias, sunflowers and cosmos are some of the easiest flowers to start with. Seed from open-pollinated and heirloom varieties grows true; seed from hybrids may not.

Harvest on a dry day. Cut the seed heads or pods into a labeled paper bag, not plastic, and leave them somewhere cool and dry for a week or two. Once they're fully dry, break the heads open, pick out the seeds, and remove leftover bits of plant, which can harbor mold in storage. Store the clean seed in envelopes inside a sealed jar in a cool, dark place.

For more detail on ripeness, cleaning, storage and germination testing, see Harvesting Seeds from Flowers.