Seed that breeds true
Eighteen crops, fifty-nine open-pollinated varieties. Every listing carries its isolation distance, germination range and seed life so you can save from it yourself.
All varieties
| Crop | Species | Varieties | Germ. | Seed life | Isolation | Notes |
|---|---|---|---|---|---|---|
| Butterhead lettuce | Lactuca sativa | Merveille des Quatre Saisons · Tom Thumb · Kagraner Sommer · Hilde II | 85–95% | 3–4 yrs | 3–6 m | Self-pollinating; isolate only for absolute purity. |
| Romaine / oakleaf | Lactuca sativa | Little Gem · Rouge d'Hiver · Cimmaron · Oakleaf Blonde | 85–95% | 3–4 yrs | 3–6 m | Bolts early by design — that is how you get seed. |
| Swiss chard | Beta vulgaris | Fordhook Giant · Rhubarb Chard · Bright Lights · Verde a Costa Bianca | 70–85% | 4–5 yrs | 800 m+ | Crosses with beetroot and leaf beet. Biennial: seed in year two. |
| Spinach | Spinacia oleracea | Bloomsdale Long Standing · Giant Winter · Monnopa · Matador | 75–85% | 3–4 yrs | 1.6 km | Dioecious — keep a good male-to-female ratio when saving. |
| Pak choi | Brassica rapa | Shanghai Green · Green Stem · Tah Tsai | 80–90% | 4–5 yrs | 800 m+ | Crosses with every other Brassica rapa — mizuna, turnip, tatsoi. |
| Rocket (arugula) | Eruca sativa | Garden Rocket · Wild Rocket (Diplotaxis tenuifolia) · Selvatica | 80–90% | 4–5 yrs | 500 m | Annual. Wild and cultivated rocket are different genera — they do not cross. |
| Tatsoi | Brassica narinosa | Tatsoi · Rosette Tatsoi | 80–90% | 4–5 yrs | 800 m+ | Brassica rapa group. Late-bolting and cold hardy. |
| Mizuna | Brassica juncea | Kyoto Mizuna · Green Mizuna | 80–90% | 4–5 yrs | 500 m | Brassica juncea — separate group from rapa, so safe beside pak choi. |
| Watercress | Nasturtium officinale | Aqua Large Leaf · True Watercress | 60–75% | 2–3 yrs | 500 m | Wants running water. Seed must not dry out completely. |
| Genovese basil | Ocimum basilicum | Genovese · Napoletano · Dark Opal · Piccolo | 80–90% | 4–5 yrs | 150–300 m | Annual. All basil varieties cross freely. |
| Dill | Anethum graveolens | Bouquet · Mammoth · Fernleaf | 75–85% | 3–4 yrs | 500 m | Crosses with fennel. Do not grow both for seed in the same year. |
| Parsley | Petroselinum crispum | Plain Italian · Champion Moss Curled · Hamburg | 60–75% | 2–3 yrs | 300–800 m | Biennial and slow to germinate — expect 3 to 4 weeks. |
| Coriander | Coriandrum sativum | Leisure · Slow Bolt · Moroccan | 70–85% | 3–4 yrs | 300–500 m | Annual. Bolts fast above 24 °C, which is convenient for seed. |
| Mint | Mentha spp. | Spearmint · Moroccan · Peppermint | n/a | — | not applicable | Grown from divisions or runners. Seed is rarely true to type. |
| Cherry tomato | Solanum lycopersicum | Gardener's Delight · Black Cherry · Yellow Pear · Isis Candy | 85–95% | 4–6 yrs | 3–10 m | Self-pollinating. Ferment the gel before drying. |
| Chilli / pepper | Capsicum annuum | Padrón · Jalapeño · Cayenne · Hungarian Hot Wax | 75–90% | 3–4 yrs | 30–60 m | All C. annuum cross with each other, hot into sweet. |
| Potato | Solanum tuberosum | Charlotte · King Edward · Pink Fir Apple · Desiree | n/a | — | not applicable | Sold as certified tubers, not true seed. Save tubers, not seed. |
| Corn (dwarf) | Zea mays | Golden Bantam · Stowell's Evergreen · Blue Hopi | 80–95% | 2–3 yrs | 400 m–1.6 km | Wind-pollinated. Isolation is measured in fields, not metres. |
Germination percentages are typical ranges for well-stored, fresh seed of that species. They are not certificates for a specific lot. Isolation distances are the minimums used by seed savers to keep a line true; wind-pollinated crops need far more.
Seed you can save from
It breeds true
Open-pollinated varieties produce offspring like the parent, provided they are not crossed. Hybrids do not — saving from an F1 gives you a lottery.
It is not owned
No variety here is protected by plant variety rights or a patent. You may save, replant, and share.
It adapts
Saved seed acclimatises to your soil and season over successive generations. Bought-in hybrid seed never does.
We publish the hard parts
Isolation distance, pollen behaviour and seed life on every listing — the information that decides whether your saved seed is true.
Start with five
Pick five crops from different families. That way nothing you grow for seed can cross with anything else in the same year.