Vegetable & Herb Seed Saving Calendar
Harvest Window Crop Seed Category Saving Method
Late Spring Spinach Orthodox Let stalks turn brown/dry; strip seeds by hand.
Early Summer Lettuce Orthodox Wait for "puffballs" (like dandelions); shake into a bag.
Early Summer Peas Orthodox Leave pods on the vine until they are brown and "rattle."
Mid Summer Coriander Orthodox Harvest when seeds turn from green to tan/brown.
Mid Summer Basil Orthodox Wait for flower spikes to turn completely brown and dry.
Late Summer Beans Orthodox Leave on the vine until pods are crispy-dry.
Late Summer Tomatoes Orthodox Ferment seeds in water for 3 days to remove gel coating.
Late Summer Cucumber Orthodox Harvest when fruit is overripe (yellow/orange and soft).
Autumn Peppers Orthodox Harvest from fully ripe (red/yellow) fruit; air dry.
Autumn Squash/Pumpkin Orthodox Scoop from mature fruit; rinse well and air dry.
Autumn Corn Orthodox Leave on the stalk until the husks are brown and papery.
Year 2 Carrots/Beets Orthodox Biennials; harvest seeds in the second year after flowering.
You’ll notice the list above is almost entirely Orthodox. Most common annual vegetables have evolved to survive winters as dry seeds. True Recalcitrant seeds are rare in a standard vegetable patch but common in perennial or tropical setups. If you expand your garden to include these, handle them differently. Do not let them dry out, keep slightly damp, plant as soon as possible.
What to do next!
Remove the Chaff - Clean!
"Chaff" is the non-seed material (dried pods, stems, husks). Removing it isn't just for aesthetics; leftover plant matter can harbor mold or insects that eat your seeds
Dry Processing Methods
Threshing: This is the "brute force" phase. Put dried pods (beans, peas) or flower heads (basil, lettuce) in a pillowcase or bucket and crush/stomp on them to break the seeds free from their housing.
Screening/Sifting: Use a series of mesh screens. You want one screen large enough to let the seed through but catch the big stems, and a second screen small enough to catch the seed while letting the dust and fine dirt fall through.
Winnowing (The Wind Method): The most effective way to remove light chaff. On a breezy day (or in front of a box fan), slowly pour seeds from one bucket to another. The heavy seeds fall straight down; the light chaff blows away.
Wet Processing (For "Fleshy" Seeds)
For tomatoes, cucumbers, and squash, you use the Decanting Method:
Mash the fruit and put the pulp/seeds in a jar of water.
Viable (good) seeds are heavy and sink.
Unviable seeds and pulp are light and float.
Pour off the "trash" at the top, rinse the sunken seeds, and dry them immediately.
CONGRATULATIONS, YOU NOW HAVE CLEAN VIABLE SEED! STORE IT AS FOLLOWS…
The golden rule for storage is Cool, Dark, and Dry. A fridge that isn’t opened often is ideal, but not often available. Store the seed in a cupboard or a back corner of a wardrobe. Somewhere humidity and light does not fluctuate. Use paper envelopes for the initial drying phase (to prevent rot). Once bone-dry, move them to Glass Mason Jars with a rubber seal to lock out moisture. If storing seed in packets then keep in a dedicated container.
Seed Longevity Guide
Storage Life Vegetable/Herb Types
Short-Lived (1–2 Years) Onions, Leeks, Parsnips, Carrots, Spinach, Chives.
Medium-Lived (3–4 Years) Beans, Peas, Corn, Carrots, Peppers, Squash.
Long-Lived (5–10+ Years) Tomatoes, Lettuce, Radish, Cucumber, Cabbage, Basil.