[Syonyk]

Unfortunately, outside some particular environmental conditions that are far from trivial to reproduce most places, seeds don't last indefinitely. The gemination rate tends to drop off fairly rapidly as a factor of years.

They're designed to survive from late summer to spring, not years or the decades that would be needed for that sort of thing.

Now, there's a ton you can do with seeds - work on optimizing various heirloom varieties of plants to your local climate (as opposed to the "one seed for all places, apply energy to the field until they behave!" approach that is widely used today), and trying to keep some genetic diversity in the seeds you use, but I don't think "random seed capsules" are likely to work over the likely timeframes involved.