Storing seeds

I live in a hot, humid climate, so I'm always concerned about my seed storage conditions. I know that cool and dry is best, but I've been wondering about two other methods.

1 - Freezing. It seems this would be safe, but I've hesitated because I don't know if it is okay for all seeds. Are there any guidelines for freezing garden seed?

2 - Vacuum packing. I use this method a lot for dried foods because we have horrible pest problems. It also keeps food from absorbing the humidity and going stale. But vacuum packing removes all the oxygen from the jar, so again, I hesitate.

Joseph, what are your thoughts on these possible seed storage methods?

Freezing is a great way to store most types of dry garden seeds. If the seed is the type that comes in a packet, and sits around on a shelf for months or years before getting planted, then it's a great candidate for freezing.

There are some tropical seeds that shouldn't be dehydrated, because the embryo dies. Those seeds should likewise not be frozen. Avocado would be an example of this kind of seed.

High moisture content in the seeds can lead to damage during freezing, therefore make sure that the seeds are well dried before freezing. If a seed smears when hit with a hammer, it isn't dry enough. If it shatters, then it's ready for freezing. I sometimes do the bite test.... If it's crunchy then it's dry enough to be frozen. If it's chewy, it's not ready for freezing.

Freeze in some kind of water-proof container. When the seeds are taken out of the freezer, moisture condenses onto the packaging. Which is fine if that's a plastic bag, or a glass jar. It's not ok for moisture to condense directly onto the seeds or a paper seed packet.

Freezing extends the storage life indefinitely. And it prevents insect predation. When they are ready for storage, I put most of my seeds in the freezer for a few days to kill seed eating insects, larva, and eggs. I don't have sufficient space to store seeds long-term in the freezer.

I don't have personal experience with vacuum packing. I store most of my seeds in glass jars with steel lids. Bugs chew through plastic bags to re-infest seeds. Neither mice nor insects can get into sealed glass jars.

This is great info! Thank you, Leigh and Joseph! I'm also in a climate with hot, humid summers (101°F, yesterday, with only about 70% humidity - pretty dry, for here! ) I have kept some all of my seeds at room temperature, because hubs keeps the house so cold that I actually throw on a blanket, if I stop moving, for long! But, I was outside a few weeks ago, planting, and made 2 mistakes. 1. I took all my seeds out, with me and 2. Forgot to bring them back in,  leaving them on the goat's grain bin. My (truly free, free-range) goat buck apparently got excited about the basket I'd forgotten, and knocked it off the back of the bin, where it wasn't casually visible - which is why it was out there, so long. I brought it back in,a few days ago, but I've been wondering if the moisture in the air from our normal humidity, plus the torrential downpours would have damaged my seeds, ruining their viability, in that amount of time? They were in cheap plastic bags, under a roof. Other than the obvious signs of mildew, or damp packages, is there a quick way to check thousands of seeds?

If the bags are still sealed, they probably protected the seeds. You'll know if they went bad if they start molding.