How long will my tomato seeds last?

If stored correctly potentially 100 years! I'm not kidding.

The oldest successfully germinated tomato seeds documented were approximately 100 years old, found inside a vintage seed packet from a 1926 Stark Bro's Seeds catalogue. The free promotional packet contained a rare variety called "Stark's Blight Resister," dated from 1926 (with seeds estimated to be from the 1925 harvest). 

Eric from the Hand Tool Rescue channel carefully tested various sterile media and conditions to coax the century-old, dormant seeds back to life. Against standard horticultural expectations—where most tomato seeds lose viability after roughly 10 years—he successfully grew a living tomato seedling from the batch.

 Unverified archaeological accounts mention potential sprouts from roughly 150-year-old seeds recovered from 1850s latrine (privy) excavations in Illinois, though well-documented controlled flower and vegetable revivals typically center around the century mark or prior verified heirloom tests (such as 80+ year old giant crimson varieties).

At Seedsavers we are currently attempting to germinate some tomato seeds we've had for 10 years - some great varieties that are less common today - we'll let you know how we get on.

Seedsavers notes a 3-year 'sow by' period on their seed packets however the seeds, if stored correctly, could be viable for up to 10 years, being germinated in ideal conditions. 

How should you store your seeds for longer viability? Seeds kept in a hot garage or humid area will die quickly. Seeds kept in a cool basement, refrigerator, or freezer last much longer. Ideally in a brown envelope in a cool, dark spot. 

But, like everything, the germination rate will fall with age. I say try them, you never know.