How to clean and store seed in autumn

Some seeds need frost to aid germination, and are therefore best sown fresh in autumn. Find out how to sow fresh seed in autumn.

Many seeds don't need a period of cold, however, and require light, warmth and water to germinate instead. They are therefore better sown in spring or, for more tender varieties, in early summer when all threat of frost has passed. Collect the seed in autumn, clean it, then store in a cool, dark spot until you’re ready to sow them.

It's a good idea to 'clean' the seeds before you store them. This involves removing the chaff, which may harbour pests and diseases and could turn mouldy or rot. It can take a bit of time, but cleaning seeds on a damp day can be very therapeutic.

Seeds that are best stored until spring include cosmos, globe thistle (echinops), hydrangea, lovage, marigold (tagetes), penstemon, red orache, sea kale (Crambe maritima), salvia and sunflower.

Here's how to collect and clean seeds.

You Will Need

• White paper
• Funnel
• Sieves
• Envelope
• Pencil
• Plastic container

Step 1

Before you get started, write the name of the seed on its envelope to avoid mix ups when planting. To start the process use a wide gauge sieve that the seed will pass easily through, shaking the seedheads above some clean paper. Some of the fine chaff will go through as well, but this will remove most of it.

Step 2

After the first sift, transfer the seed and the fine chaff into another finer sieve, such as an icing sugar sieve or shaker. This time the fine chaff will land up on the paper and the seed will remain in the sieve.

Step 3

Tip the cleaned seed into the labelled envelope, using a funnel if necessary. Seal, then put this envelope into a waterproof container for storage. Store your dried packed seeds in a cool dark place. Don't put in spots that are hot, moist or too light as the seed may rot or fry.