Storing seeds long term
Specifically foxglove seeds. What's the best way and how long can you expect a good percentage of seeds to remain viable?
Assuming in a container in the fridge might be the best bet?
How long is long term? I can't see why you'd want to keep them more than a year, since you could collect fresh ones every year? As a general rule, the smaller the seed, the longer it stays viable, so
probably would keep a few years in a paper packet in the shed. Just don't put them in a plastic bag; they need to be able to breathe.
More if I had a particular variety I wanted to keep using because I couldn't guarantee the collected seed as coming true.
To my knowledge they will remain viable for 3 or 4 years. I've never bothered with keeping any seeds in the fridge - just paper packets ( used envelopes are handy ) and kept in a cool, dark place.
As you suggest, if you are after retaining the seeds from a specific variety, the results may be a bit hit and miss if the flowers have been openly pollinated.
If you decide to store them in a fridge then you need to use an airtight container as fridges remove moisture and will dry them out (ie kill) them. In this case use zip-lock type plastic bags to hold the seed and expel as much air from the bag as you can before sealing in something like a tupperware box and putting in a fridge. Seed banks do exactly that but freeze the seed to -20C which is the temperature that home feezers are ideally set at, so you could potentially keep them for decades if you have a freezer.
A trowel in the hand is worth a thousand lost under a bush.