How long do you give them?

Seeds that are past their prime. How long do you give them to germinate? Obviously the answer could get quite scientific. Depending on the variety and how past their prime. Not to mention the little matter of region, location, weather, compost, propagator, window cill, tunnel/greenhoue, cold frame. Apart from all those very possible & real variables. What’s your ballpark time scale?

That's way too complicated for me! A lot depends on how much I want to grow the seed in question - is it rare, the only one I have, in which case I might be more patient. Some seeds are notoriously slow to germinate so I'll set the pots aside and forget about them.
If its something common, like today's old carrots and leeks, which were a couple of years past their sow by dates, I just scatter them and forget them.
I find "forgetting" seeds is very easy. I wouldn't waste time, effort and compost on old, common seeds.
I'm guessing that you have some particular seeds in mind? Care to share?

I can't say I've ever given it much thought. I've sown some old R3d Robin seeds that as yet haven't popped, although most of the others have. I suspect I will resow and bung the unpopped ones into a corner and forget about them. I haven't any special seeds I would stress about too much.

That's way too complicated for me! A lot depends on how much I want to grow the seed in question - is it rare, the only one I have, in which case I might be more patient. Some seeds are notoriously slow to germinate so I'll set the pots aside and forget about them.
If its something common, like today's old carrots and leeks, which were a couple of years past their sow by dates, I just scatter them and forget them.
I find "forgetting" seeds is very easy. I wouldn't waste time, effort and compost on old, common seeds.
I'm guessing that you have some particular seeds in mind?  Care to share?

Not really anything particular. Currently it’s many different varieties of eryngium that have not shown any signs of life. But with my seed hoarding, and not actually sowing very much the last couple of years. I seem to have a lot of past their best seeds. I will be using your scatter and forget with a few.

According to Chiltern Seeds, Eryngium are slow to germinate - detailed instructions at https://www.chilternseeds.co.uk/item_526...otts_ghost

According to Chiltern Seeds, Eryngium are slow to germinate - detailed instructions at https://www.chilternseeds.co.uk/item_526...otts_ghost

Wow ! they can take a while. 

I’ve just come up with a very Veggie idea   , while I was eating my tea. I’m going to mix lots of my old flower seeds with some compost and scatter it around the post box bed. I don’t usually like just scattering seeds because we have so many voles & mice. I don’t think the seeds stand much of a chance. I’m hoping the additional compost will give them a little more of a chance. If I get lots of germination. I can transplant some of the seedlings.

What a brilliant idea. There are lots of voles & moles, and little birds here too but I take the view that old seeds won't grow in their packets and, at least they have a fighting chance if scattered - just as wild seeds, sown by Mother Nature do.

Im in the same situation as you SC - lots of seeds and quite a lot of them are getting past their best.

I'm not normally very patient, but then I have been quite busy and known to let seeds sit in their trays for quite a few weeks before resowing something different.

Under normal circumstances, I'd probably not let anything sit for more than a month before they're chucked.