You can save seeds from most garden vegetables, but the results depend on the crop. Beans, peas, lettuce and tomatoes are the easiest because they mostly pollinate themselves, so the seed grows true with little effort. Squash, cabbage-family crops, carrots and corn cross-pollinate with neighbouring varieties, so they need isolation. Start with heirloom or open-pollinated varieties, and save from healthy plants only.
Which plants are best for seed saving?
University of Illinois Extension explains that open-pollinated plants generally produce seed that grows true to type. Heirlooms are a special kind of open-pollinated plant, usually passed down for flavour or colour. Hybrids are deliberate crosses of two parents; their seed usually does not resemble the parent, may be sterile and is often patented, so it is a poor choice for saving.
| Pollination | Examples | Isolation |
|---|---|---|
| Self-pollinating (easiest) | Peas, beans, lettuce, tomatoes | Tomato 10–50 ft; bean, pea and lettuce 10–20 ft |
| Insect-pollinated | Squash, melons, cabbage family, cucumber, onion, carrot, radish | Squash, melons, brassicas, cucumber, onion and radish: 800 ft to ½ mile |
| Wind-pollinated | Corn, beet, spinach | Corn 800 ft to ½ mile; beet and spinach 800 ft to 1 mile |
| Self-pollinating but needs space | Pepper, okra, lima bean | Pepper 300–1,600 ft; okra 500–1,600 ft; lima bean 160–500 ft |
Distances come from the Seed Savers Exchange table as quoted by University of Illinois Extension. Plants of different species in the same family do not cross, but two varieties of the same species do.
How do you keep varieties from crossing?
There are three methods, and you can combine them.
- Time: stagger planting so two varieties do not flower together.
- Containment: cover flowers with paper, nylon or floating-row-cover bags, and hand-pollinate with a cotton swab or small brush.
- Distance: use the spacing in the table above. If you cannot reach it, use time or containment instead.
How do you harvest and dry seeds?
Dry seed (beans, peas, onion, carrot, corn, flowers, herbs)
Harvest mature, dry seed. For small, light seed, cut the seed heads just before they fully dry to limit shattering. Finish drying in a single layer on a screen in a cool, well-ventilated spot. Paper or nylon bags catch any seed that drops.
Wet seed (fleshy fruit with a gel coating)
Scoop or crush the fruit, add a little water in a jar and let the seed ferment for 2 to 4 days, stirring daily. Fermenting breaks down the gel. Viable seeds sink; pulp and poor seeds float, so pour off the top layer and water. Spread the seeds on a paper towel or fine screen to dry. Tomatoes are the classic example, and this method suits other fleshy fruits too.
How do you store saved seeds?
Keep seeds cool and dry in paper envelopes. For long-term storage, put the paper envelope inside a glass jar, which keeps pests out. Label every container with the plant name, variety and date. Test old seed before you rely on it with our seed germination rate calculator, and plan how much to sow with the seed quantity calculator.
When should you start saving seeds?
Pick the plants that did best: healthy, productive and true to type. Do not save seed from plants with disease. Start with one easy crop this year, such as beans or lettuce, and add harder crops once you have the routine. Use our guide to planting seeds and when to start seeds indoors to sow what you saved.
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Frequently asked questions
Can I save seeds from store-bought vegetables?
Sometimes, but many grocery vegetables are hybrids, so the seed may not grow like the parent, and it may be sterile. Open-pollinated or heirloom seed packets are a safer start.
Why did my saved squash seed grow odd fruit?
Squash cross-pollinates with other varieties of the same species by insects, so a neighbour’s variety may be the other parent.
How long do saved seeds last?
It depends on the crop and storage. Cool, dry storage in labelled envelopes helps, and a germination test tells you for certain.
Reviewed November 2026. Sources: University of Illinois Extension: How to save seeds
