Planting & seeds

Are my old seeds still good?

Typical shelf life by crop, from one year for onion and parsnip to five for tomato and cucumber, plus a paper-towel test that settles it.

How this works

Towel test: 10 seeds in a damp paper towel inside a loose bag, somewhere warm, 5–10 days. Cool, dark and dry storage roughly doubles every shelf life.

Questions people ask

How do I test old seed?

Roll ten seeds in a damp paper towel in a bag somewhere warm. Count how many sprout within the crop's normal window. Seven of ten means sow a little thicker; two of ten means buy fresh.

Which seeds go bad fastest?

Onion, leek, parsnip and parsley are done in about a year. Sweet corn and peppers are middling. Tomato, cucumber and the squash family stay good for four or five.

How should I store seed?

Cool, dark and dry, and the dry matters most. A jar with a silica packet in the fridge beats a shed drawer by years.

More planting & seeds tools

All 29 garden calculators →