Perpetual Seed Line Protocol
Buy the seed once. Keep it for good.
A seed line can run for as long as someone keeps sowing it — if three conditions hold every season. Miss one and the variety drifts, crosses or weakens. Every Seedback lot records whether they were met.
01 · The three conditions
What makes a line last.
Start open-pollinated. Use open-pollinated or heirloom varieties. An F1 hybrid's seed splits into different plants in the next generation, so the line ends with the first harvest.
Stop the crossing. Keep varieties of the same species apart by distance, flower at different times, bag the flowers, or hand-pollinate. Pollination type sets how hard this is: self-pollinated beans and tomatoes are easy; wind-pollinated corn is not.
Save from enough plants. Seed from one or two plants narrows the variety each season until it loses vigour. Each crop in the Seed Library shows the number of plants to save from.
02 · Reading the packet
Choose seed you can keep.
| On the packet | Decision |
|---|---|
| Open-pollinated · OP · Heirloom · Heritage · Non-hybrid | Use it. |
| F1 · Hybrid · F1 Hybrid | Do not save from it. |
| PBR mark · Plant Breeder's Rights | Grow it for yourself; do not sell, swap or label it. |
| Sweet corn "Supersweet" / sh2 | Mostly F1 — check each one. |
One seller can stock both kinds side by side, so check the line, not the shop. Buy each crop from two or more sources when you can: a wider genetic base keeps a line strong. Buy within Australia — importing seed brings biosecurity rules.
03 · Five staples for a resilient garden
Calories that keep coming back.
| Crop | Pollination | Keep varieties apart | Save from | Open-pollinated examples | Saving |
|---|---|---|---|---|---|
| Bean · BN | Self | 3–6 m (runner beans cross by insects: further) | 10+ plants | Purple King, Borlotti, Blue Lake | Pick pods dry and papery on the vine; shell, dry, store. |
| Tomato · TM | Self | 3–10 m (potato-leaf types 15 m), or bag the trusses | 6 plants | Black Krim (TM-0001), Tommy Toe (TM-0002), Grosse Lisse, Roma | Ferment 3–4 days, rinse, dry in shade. |
| Corn · CN | Wind + insects | 500 m to 2 km, or tassel 2–3 weeks apart, or bag and hand-pollinate | 50–100 plants for the variety (about 20 if eating only) | Golden Bantam; Hopi Blue and Bloody Butcher for grain | Dry the cobs on the stalk; take seed from the middle of the cob. |
| Pumpkin · CU | Insects, within a species only | About 500 m, or tape flowers shut and hand-pollinate | 5–10 plants | Queensland Blue, Jarrahdale (C. maxima); Waltham Butternut (C. moschata) | Cure the fruit 2–3 weeks, then wash and dry the seed. |
| Sweet potato · TB | Clone | Not needed | Healthy tubers | Local heirloom lines | Keep tubers; sprout slips in spring and plant them. Renew with clean stock if yields fall. |
Cucurbita maxima, C. moschata and C. pepo (zucchini included) do not cross each other: grow one variety per species and they stay true in your garden — a neighbour's pumpkins are another matter. Sweet potato, potato and garlic are clone lines: we count them in cycles, not generations.
04 · Storing and renewing
A seed bank you keep alive.
- Dry seed fully, then seal it in an airtight jar with silica gel. Keep it cool and dark; the fridge is fine, the freezer only for seed that is completely dry.
- Before each season, test ten seeds on a damp paper towel. Under seven sprouting means re-saving that line this season.
- Rough seed life when stored well: beans about 3 years, corn 3–5, tomatoes 4–6, pumpkins 5–6. Each crop's figure is in the Seed Library.
- Hold two seasons of spare seed and sow every line each year, so the bank renews itself.
- Store in two places — at home and in a second kit — so one loss does not end the line.
05 · Declaring a line
What a lot record says about the seed.
When you declare a line, four extra facts go on the record:
- Pollination — self, insect, wind or clone.
- How crossing was stopped — distance in metres, weeks apart, bagged, hand-pollinated, or one variety per species.
- Parent plants — how many plants the seed was saved from.
- Not PBR — the variety is not under Plant Breeder's Rights.
The record then shows one of four marks:
- Comes true crossing was stopped and the seed came from at least the crop's recommended number of plants.
- Cross risk crossing was not stopped, or too few parent plants.
- Not recorded the planter did not record isolation.
- Clone line grown from tubers, cloves or cuttings.
06 · Crop group codes
Two letters, four digits.
| Code | Group |
|---|