How long are seeds of plants typically viable? In other words, how long after a seed has been plucked from a plant can it be planted into the soil and produce a plant?

Too many variables to make a generalized prediction. Environmental conditions of storage are very important. In any sample, all the seeds don't die at once, their viability, expressed as %, diminishes over time. Warm-humid and changing conditions is the worst, dry-frigid, after preparing the internal average moisture, is best... probably centuries. A fridge will keep most viable for maybe 5-10 years. In a cool, dark place, place maybe a couple of years.

Edited April 30, 20223 yr by StringJunky

https://www.croptrust.org/our-work/svalbard-global-seed-vault/faq-about-the-vault/
 

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HOW ARE THE SEEDS STORED?

The seeds are stored at minus 18°Celsius (minus 0.4°Fahrenheit). The seeds are sealed in specially-designed four-ply foil packages that are placed in sealed boxes and stored on shelves inside the vault. The low temperature and moisture level ensures low metabolic activity, keeping the seeds viable for decades, centuries, or in some cases thousands of years.