Seed storage desiccants

I am just starting to learn to save my own seed and have been trying to figure out how to keep ideal storage conditions.

One of the things I have learned about is the optional use of desiccants in order to keep moisture low and prevent molding.

My first trial involved utilizing a commercial product. I found what is essentially kraft paper packets filled with clay which would help regulate humidity in my seed containers. The specific item that I used was Mirco-Pak.



My second trial is just in its infancy but is a much simpler concept. I utilized dried rice and just add a little bit to each seed container on the bottom before seeds are added. If it is good enough to resurrect electronics from water damage, I figure it can regulate humidity in a small container.

Do you use a dessicant for seed storage? Is it overkill?

I have sometimes, but neglected to with these…
This is after drying for over a week in the kitchen.

I reuse desiccants that come with whatever item I bought (doesn't happen all that often). Aside from longterm storage (freezer), I keep my seeds in ammo boxes with some desiccant packets.

Clay McGowen wrote:I have sometimes, but neglected to with these…
This is after drying for over a week in the kitchen.

Ohh no!

I lost a container of pumpkin seeds when I realized I needed to do something different. A tough lesson for sure.

I use to use powdered dry milk. I’d put some in the bottom of the container and then pile the seeds on top. It worked ok. Just had to change out the powdered milk if I discovered my seeds weren’t dry enough. It was messier than using desiccant packets.

Currently I’m using those little dissident packets. I dry them in my solar dryer (I don’t own a working oven) as needed. I get a steady supply for free from the veterinary hospital and my local pharmacy. Of course, I gift the people there with fresh produce as a thank you. It’s a good trade as far as I’m concerned. Sure I could buy the packets on Amazon, but why spend money when I don’t have to (or generate more unnecessary trash).

Cat litter is a quick and readily available alternative, especially if you're away from home and can't follow your normal procedure.

Anything you use will reach ambient humidity and stop absorbing any more. The great difference with silica gel is that the kind with dye in it will tell you when that happens. With rice, etc, you have to keep renewing it on a schedule since you can't tell.

An old seedsman told me he puts a sheet of paper in there when closing the container. If the paper crackles when crumpled a bit, the air is still pretty dry. If it has started to merely rustle, you're behind on renewing the absorbant stuff. If it is limp, you really need to dry things out pronto!

Wow, that would be tragic.
I never had moldy seeds.  I wash seeds, dry bigger ones in dehydrator, tiny ones air dry for few days, then keep all seeds in used pills/meds vials, stored in metal box.

A desiccant adds to the expense, so I prefer to really dry them well. Easy peasy since I do not deal in industrial quantities for seeds. If they are not well dried before they are put into storage is when you will get into trouble.
I spread them where they won't get wet, out of the sun, inside the house. [The sun will warm the seed and the absence of sun will cool the seed: The difference could create a tiny bit of condensation, which is deadly for the quality of your seed==> low germination].
Only when they are good and dry do they go in little party favor boxes and the whole thing in my office, inside the house and in the dark.
By the way, the refrigerator is not a good place for them either: Once they are dry, they do not need to be cold: Going from a warm 70F to 35F will also cause condensation and wreck the quality of the seeds.

Seeds keep better in paper than in plastic.  This according to Territorial Seeds founder Steve Solomon.  You're not, I assume, creating a time capsule or a bomb shelter, I assume.

If you need seeds to last longer than they will in paper, that's a skill issue about your gardening, not a need to save seeds forever.

As for larger seeds, if you really have no place in your home that has the ability to dry large seeds when they're still in the pods, just keep them away from the kitchen and near the floor, since humidity rises.

If you really can't save large seeds even after all that, you've likely got the wrong plant or variety for your area in the first place.

I just bought some of these food-grade silica gel packets to use in both bulk corn storage and my seed saving: https://www.amazon.com/dp/B0CY8HY8PJ

I have nothing to report yet, but my reading suggested that silica gel is safe and tame. Is it something permies steer clear of?

(I've also used white rice in the past.)

I really like the rice idea, I'll have to try that one easy enuf.

Correct me if I'm wrong but the dessicant packs are essentially silica? Which leads me to believe some finely ground up rocks might just do the trick? (Just hit with hammer until pulverized)

Like Clay posted about, I too had the mold form on some squash seeds I guess weren't dry enuf. The only thing I had on hand that I thought might work to save them was a bucket of wood ash.

So I looked it up and sure enuf it's a thing, so I swished them around in a bit of the ash, let them sit out for another week and we'll see! It does appear to have stopped the mold, maybe they'll be ok...and maybe a little sprinkle of ash in each jar before storage in the future is a good thing?

I gave up on storing in paper envelopes after insects and mice seemed to find thier way in no matter what I did. I think some tiny insects must have been in wild seeds I collected, then its like they transfered over to the other paper packs!? Glass jars for me now.

Cole Tyler wrote:
Correct me if I'm wrong but the dessicant packs are essentially silica? Which leads me to believe some finely ground up rocks might just do the trick? (Just hit with hammer until pulverized)

I think you are actually right, and Silica gel is a form of silica with specific pore characteristics. Other rocks might work pretty well too, once that either have an ability to chemically bond to water when they are dry or have a porous structure that water gets into (but can't get out of so easily. The amount absorbed depends on the humidity and the temperature as well as increasing to a maximum with time.


source

I suspect soft rocks like chalk and also activated charcoal might be good as they have large pore surface areas for the water vapour to get into. Dry wood ash might act chemically as well as mechanically so probably twice as effective, although I'm not sure how the alkalinity would act on the seeds long term storage ability?

just about everything shipped these days comes packaged with a silica pack (boots, batteries, electronics, etc etc.) - you can save them and reuse them no problem - ask your friends to save them too.. (they are great in tackle boxes, ammo boxes, tool boxes etc. as well)

it is ESSENTIAL to be sure your seeds are dry dry dry before you package them..in late summer/fall i have plates all around my house on books with seeds sitting on scraps of parchment...patience is key - 2 weeks  seems safe for internal seeds (peppers, tomatoes, squash, cukes etc.),  herbs you harvest  dry as a bone on a dry afternoon - them store the stalks til dry dry dry.. beans harvest crispy.. then dry more

did i say dry?? you can't rush the process .. putting them on plates gives insects a chance to skedaddle as well

to store the seeds, i use coin envelopes ..

https://www.staples.ca/collections/coin-envelopes-8902

they are pricey but work great a they are tough and breathe (i would advise against airtight containers) use a paper clip to seal them up as opposed to to wetting the glue flap you can re-use them until there is no space to write... i store the envelopes in plastic shoe boxes, with silica and those go up in a wood cabinet in a dry place in the house that has a door that closes (a kitchen cupboard up high would work well so long as mice can't get in)..

not much more to it but all of the above really does work reliably

good luck - cheers!

Geoff Colpitts wrote:
You're not, I assume, creating a time capsule or a bomb shelter, I assume.

I'm never going to live down my shameful treatment of the I assume twins.