Saving summer’s seeds: start with drying

Small, wrinkled seeds are spread out on paper. Some are green, others browner. The reader is asking about nasturtium seeds and when they are ready to harvest. If you have gathered a little pile too, the next step is to keep it organised before it goes into an envelope.

Start with ripe seeds

Seeds ripen in different ways, and colour changes depend on the plant. Ideally, collect in dry weather and check what that particular seed looks like when ripe. Drying an unripe fruit or seed does not automatically make it capable of germinating.

Dry and clean before storing

1. Keep different kinds of seed separate and allow the harvest to dry with good air circulation.
2. Remove loose plant debris. Pack the seeds only once they are dry.
3. Label paper envelopes with the plant’s name and collection date. Store somewhere cool and dry, protected from damp.

Write down what you want to remember

Which plant did the seeds come from? Where in the garden was it growing? Add a short note while you remember. That gives next spring’s sowing a clear starting point, even if you have collected several envelopes over the autumn.