Old Seeds: Sow, Test, or Replace?
A quick decision rule for old seed packets: inside the typical range, sow; just past it, test; well past it, buy fresh. When thick sowing is fine and when...
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Old Seeds: Sow, Test, or Replace?
Find the packed-for year and the crop's typical seed life. Inside the range, sow. Up to 2 years past it, test first. Well past it, replace. The Seed Viability Check applies this rule to every packet in your stash.
The Rule
| Packet age | Call |
|---|---|
| Inside the crop's typical range | Sow at the normal rate |
| Up to 2 years past the range | Run a 10-seed paper towel test |
| More than 2 years past the range | Buy fresh seed for the main planting |
For 1-year seed like onion and parsnip, the test window is 1 year, not 2. Typical ranges are in How long do vegetable seeds last?
When Old Seed Is Fine to Use
- Cheap, fast crops sown thickly anyway. Lettuce, radish, arugula, and mustard greens. Sow heavy and thin.
- A test came back 50 percent or better. Sow thicker and expect some weak seedlings.
- The variety is irreplaceable. Heirlooms from family or a discontinued line. Sow all of it thickly, then save fresh seed from the plants that grow.
When Old Seed Wastes a Season
- Long-lead indoor crops. Onion, leek, pepper, and celery go in trays 8 to 10 weeks before last frost. A failed tray costs weeks you cannot get back. See the indoor seed-start calendar.
- One-shot plantings. Sweet corn blocks, a single fall carrot sowing, or a bed with a narrow window. A thin stand is hard to fix.
- Seed that sat in heat or got damp. The chart assumes cool, dry storage. Treat badly stored seed as at least one category worse.
Old Seed Also Grows Weaker Plants
Old seed that does sprout often comes up slower and less vigorous than fresh seed. That matters most for crops that need a fast start, like carrots competing with weeds.
Next Steps
- Sort your stash on the Seed Viability Check and use its Shop Seeds Now button for the replace list.
- Store what you keep in a sealed jar: How to store leftover seeds over winter.
- Pick which varieties earned a spot next year with Variety Verdict.
Sources: Illinois Extension, Iowa State University Extension, Nebraska Extension G2090.