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.