How to save
seed
Maturity, processing, drying and storage — the four steps that decide whether your seed is viable next year.
How to save seed
Saving seed is mostly about timing and dryness. Get the seed fully mature, dry it fast, and store it cold and dry. Everything else is detail.
1. Let it mature on the plant
Never save from the earliest or the best-looking fruit. Seed from an over-ripe fruit that has gone slightly past eating quality has had longer to develop. For beans and brassicas, let the pods dry on the plant until they rattle.
2. Separate the seed from the flesh
Tomatoes and cucumbers need the gel around the seed fermented off — three days in a jar of water, then rinse. Peppers, brassicas and herbs are dry-processed: shell the pods and winnow.
3. Dry it properly
Aim for 8 percent moisture or below. A week in a warm dry room with air movement, spread thin on paper. Seed should snap, not bend.
4. Store cold and dry
Sealed jar, silica gel sachet, 5 °C. Every 10 °C drop roughly doubles seed life. A fridge is better than a cupboard; a freezer is better still for long-term storage if the seed is properly dry.
5. Test before you sow
Ten seeds on damp kitchen paper, in a warm place, for the number of days on the catalogue listing. Seven out of ten means the lot is fine. Three out of ten means sow thick or buy fresh.