How to store your seeds properly

Storing seeds, whether they come from your own garden or from opened seed packets, is a simple step towards greater self-reliance in the garden. A seed is not an inert object, but a living organism at rest. When stored correctly, it can remain viable for several years and help extend your growing cycle season after season.

At Cycle en Terre, we see seed saving as a natural continuation of gardening: growing, harvesting, storing and passing on. A small step towards greater independence, savings and biodiversity.

1. The enemies of seeds: heat, moisture and light

Three factors accelerate seed ageing and reduce germination rates:

• Heat: stimulates biological activity and shortens lifespan.

• Moisture: encourages mould and can trigger premature germination.

• Light: disrupts the seed’s dormant state.

Sudden changes in temperature and humidity are also harmful. Seeds stored in places like greenhouses, sheds or windowsills are repeatedly “woken up”, which slowly depletes their energy reserves.

2. Ideal storage conditions

Four simple rules:

• Dry: moisture is the main enemy.

• Cool and stable: ideally between 5 and 10 °C (41–50 °F).

• Dark: protect from direct light.

• Consistent: avoid sudden changes.

A cool, dry room or the vegetable drawer of a refrigerator (in an airtight container with a moisture absorber) works very well. Avoid damp cellars or places with strong seasonal fluctuations.

3. Choosing the right containers

• Paper or kraft envelopes: suitable in dry environments.

• Airtight glass jars, metal or plastic boxes: protect against moisture and rodents.

• Moisture absorbers (silica gel, dry rice): help keep air very dry.

Tip: never store damp seeds in an airtight container. Let them dry completely first.

4. How long do seeds remain viable?

• 1–2 years: parsnip, onion, parsley, corn.

• 3–5 years: lettuce, cabbage, carrot, cucumber.

• 5–10 years: tomato, aubergine, squash, melon, beans, peas.

Tomato seeds can stay highly viable for nearly ten years, while parsnip often loses vitality after just two seasons.

5. Germination test

1. Place 10 seeds on a damp paper towel.

2. Cover with a plate or plastic bag.

3. Keep in a warm place without direct sunlight.

4. Count how many seeds sprout.

If 7 out of 10 germinate, you have a 70% germination rate. Sow a little more densely.

6. Practical storage tips

• Close packets with a paperclip or clip.

• Store them upright, like index cards.

• Always note the species, variety and year of harvest or purchase.

Summary

Storing seeds means extending the cycle of life in your garden and gradually building your own reserve of biodiversity. With a cool, dry, dark and stable place and suitable containers, your seeds can remain strong for many years.

At Cycle en Terre, we select organic, open-pollinated and local seeds to support gardeners on their path towards greater autonomy and a deeper connection with their land.