Seed saving starts with one decision that most guides skip: you can only save seeds reliably from open-pollinated varieties. Seeds from F1 hybrids will not produce plants matching the parent. Getting that right first makes everything else straightforward.
Quick Answer
Easiest crops to start with: peas, French beans, runner beans, lettuce, and tomatoes. All are self-pollinating — they do not require isolation from other varieties to come true to type.
The F1 rule: seeds from F1 hybrid plants will not produce offspring with the same characteristics as the parent. Always check the seed packet — if it says F1, do not save from it. Save only from open-pollinated or heirloom varieties.
Storage: cool (45°F or below), dry, dark. A glass jar with a desiccant sachet in the fridge is close to ideal. Seeds stored this way maintain viability for 3–6 years depending on the crop.
According to University of Minnesota Extension, tomatoes, peppers, beans, and peas are the best choices for seed saving because they have self-pollinating flowers and seeds that require little special treatment before storage. Self-pollination means the flower fertilises itself before opening — pollen never travels between plants, making cross-pollination with neighbouring varieties a non-issue. Illinois Extension (October 2025) identifies the first step as distinguishing between open-pollinated and hybrid varieties — seeds from hybrid plants will not reliably carry the parent’s traits into the next generation.
Which Spring Crops to Save From — and How Difficult Each Is
| Crop | Difficulty | How to Harvest | Key Notes |
|---|---|---|---|
| Peas and broad beans | Easy | Leave pods until fully dry and rattling. Harvest before wet weather. Shell and dry indoors for 2 further weeks | Self-pollinating. Mark your best-producing or most disease-resistant plants early; leave those pods to mature |
| French and runner beans | Easy | Leave pods to turn brown and dry on the plant. Harvest before heavy rain. Shell and dry further indoors | Self-pollinating. Select pods from earliest-maturing plants if earliness matters to you |
| Lettuce | Easy — requires patience | Allow 1–2 plants to bolt fully. Cut the stalk and place upside down in a paper bag to catch seeds as they ripen | Self-pollinating. Produces hundreds of seeds per plant. Separate varieties by 10–20 feet to reduce crossing |
| Tomatoes | Easy — requires fermentation | Scoop seeds from a ripe fruit into a jar with a little water. Ferment 2–3 days. Rinse, dry on paper, store | Self-pollinating. Fermentation dissolves the germination-inhibiting gel coating and kills some seed-borne pathogens. Open-pollinated only |
| Courgettes, cucumbers, squash | Medium — isolation needed | Leave one fruit to mature far beyond eating stage until large and hard. Cure 2–4 weeks, then scoop and dry seeds | Cross-pollinating. Grow only one variety per species if saving seed, or use isolation bags on flowers |
| Carrots, beetroot, parsnips | Hard — biennial | Need two growing seasons to set seed; must overwinter and flower in the second year | Not practical in cold climates without overwintering under cover. Begin with the easier crops above |
How to Dry and Store Seeds
Moisture is the primary enemy of stored seeds. SDSU Extension’s seed storage guide (June 2025) is explicit: viability declines with age and is directly affected by storage conditions. Spread cleaned seeds on paper in a single layer and allow them to dry at room temperature for at least two weeks — seeds that feel dry to the touch still contain internal moisture. Place dried seeds in paper envelopes inside a sealed glass jar with a desiccant sachet. Label with crop name, variety, and date. Store in the fridge at 45°F or below.
What to Do
- Select the parent plant deliberately— save from the earliest producer, best flavour, or most disease-resistant plant. Not the average one
- Mark seed plants at harvest time— tie string around the best pea or bean plants when harvesting the rest; leave those pods to dry fully
- Dry for at least 2 weeks after harvest— spread on paper in a single layer. Seeds that feel dry may still contain moisture inside
- Store in glass, not plastic— glass jars with a desiccant sachet seal moisture out more reliably. Label clearly with crop, variety, and year
- Test viability before planting— 10 seeds on damp kitchen paper; keep warm. Discard the batch if fewer than 7 of 10 sprout
Common Mistakes
- Saving from F1 hybrids— offspring are genetically unpredictable. Check the packet before selecting plants; F1 is clearly marked on commercial seed
- Harvesting before seeds are fully mature— pods should be fully dry on the plant; tomato fruit well past eating stage before seed harvest
- Skipping the tomato fermentation step— the gel inhibits germination. Two to three days of fermentation removes it and improves germination rates
- Storing seeds warm or in humid conditions— a kitchen cupboard near the cooker is among the worst locations. Heat and humidity accelerate viability decline faster than age alone
This Season
- Check seed packets now — mark any that say open-pollinated or heirloom
- Mark your best-performing plants as seed candidates early
- Leave one or two lettuce plants to bolt deliberately
- Leave bean and pea pods on marked plants to dry fully
At Harvest
- Dry seeds on paper for 2 weeks before storing
- Ferment tomato seeds for 2–3 days before drying
- Store in labelled glass jars with desiccant in fridge
- Test viability on kitchen paper before sowing next spring