Saving cucumber seed
Long-lived seed and a straightforward fermentation method — but parthenocarpic varieties complicate things, because they fruit without pollination and therefore without viable seed.
- Life cycle
- Annual
- Pollination
- Insect-pollinated
- Isolation
- 500 m–1 km, or bagging
- Seed life
- 5–10 years
- Yield
- 1 fruit gives 150–300 seed
Cucumber seed keeps longer than almost anything else here — properly dried and stored, five to ten years is normal. The processing is a two-day fermentation, the same idea as tomato.
The complication is variety type. Most modern indoor cucumbers are parthenocarpic: they set fruit without pollination. That is excellent for growing under cover, and useless for seed saving unless you deliberately hand-pollinate.
The protocol
- 1
Check the variety type
If it is parthenocarpic, hand-pollinate deliberately with a male flower, or the seed will be empty. If it is a standard variety, insects will have done it.
- 2
Let the fruit go yellow and swollen
Well past eating stage — a month or more past. The skin turns yellow-brown and hard, and the fruit is huge.
- 3
Scoop the seed cavity
Cut lengthways and scoop the seed and gel into a jar. Add a little water.
- 4
Ferment two to three days
Until the gel breaks down and the viable seed sinks. Stir daily, then rinse clean.
- 5
Dry and store
A week on a plate, then a sealed jar. Viable five to ten years.
What goes wrong
Parthenocarpic varieties. Fruit without pollination means seed without an embryo. Hand-pollinate deliberately or do not save seed from them.
Harvesting at eating stage. A cucumber you would eat is nowhere near mature seed.
Crossing with other Cucumis sativus. Including ornamental and pickling types. Bag if you are growing more than one.
Saved seed from this crop?
Germination rates, what came true and what crossed — post it and let other growers learn from it.
All 14 protocols
Annual, biennial and vegetative crops all save differently. The index compares them side by side.