Growing Plants from Seeds
If you want to avoid pricking out seedlings later, sow in modules, a few seeds per cell. After germination, pinch out all but the strongest seedlings.
Buying and Saving Seeds
Most seeds are sold in a plastic or foil sachet that preserves them until opened. Seed in paper packets ages more rapidly. Keep the packet, as it will give growing recommendations and a “use by” date, after which unused seed deteriorates.
Homegrown seed is usually worth saving, but choose healthy plants with the best seedheads. Seeds must be mature, but not so ripe that they are already being shed. Enclose dry heads and capsules in paper bags before cutting them off, then label and store the bags. Spread damp seeds out to dry in a warm, airy place. Dry fruits well and store intact, or extract and dry the seeds.
Storing and Treating Seeds
Keep purchased seed in its packet (resealed if it has been opened), and saved seeds in envelopes or paper bags marked with the date of harvest. Store in a dark, dry, well-ventilated place, or in tins with one or two sachets of silica gel to absorb moisture. Aim for conditions that are frost-free but below 41°F (5°C).
A few seeds need special treatment to speed germination; this will be detailed on the packet. For example, hard seed coats that are slow to absorb moisture can be nicked with a knife (chipped) or rubbed with sandpaper (scarified), or the seeds can be soaked in warm water overnight. Other seeds may need to be chilled in the refrigerator to simulate winter conditions.