Storing Purchased Seeds

[Too Tall Toms]

I got all of the tomato seeds that I ordered a few weeks ago, so now I'm wondering what is the best place to store them until it's time to plant them? I'm not growing them myself but I found a local greenhouse to do it for me.

[Fusion_power]

For short term storage, you can place them in a jar with a tight lid. For long term storage, toss in a couple of packets of desiccant and put the jar in your freezer. The crucial key is that the seed must be VERY dry. That is why you need desiccant.

DarJones

[Too Tall Toms]

Some of them are sealed in plastic bags and some are sealed in those "paper" envelopes that you typically get seeds in.

Is from now until late March or early April considered short term?

[Fusion_power]

Less than a year is short term.

DarJones

[Hastings]

Freezing the seeds doesn't do anything to their germination rate?

[Fusion_power]

Yes, freezing them does do something to their germination rate. It makes it stay high for long term storage presuming that other storage requirments are met. Several people who post here do just fine storing seed at room temperature, but when I consulted a professional seed technologist with this question a few years ago, the answer was unequivocal. First store them dry. Second store them cool. Third, for long term, store them dry and very cool in a sealed container. Fourth, for ultra long term storage, store them VERY dry and VERY cool and in a reduced oxygen hermetically sealed container.

Dry seed will keep in an envelope just fine for 3 years at room temp.

Dry and cool could be in containers under the bed and would be good for 3 to 10 years for tomato seed but will probably get in trouble with pepper seed after 3 years.

Dry and very cool would get you up to 15 years for tomato and will keep pepper seed in good condition for up to 10 years.

Storage for ultra long term is really not what most folks will do, but if you want to do it, it requires special equipment and oxygen absorbing chemicals in glass containers that are hermetically sealed by melting the glass and closing it. Start by ultra drying the seed. This step requires a dehumidifier chamber. Then place the ultra dry seed in a glass tube filling it about half way. Place oxygen telltale chemicals to almost finish filling the tube. Use a torch and melt the glass and close it off. The entire tube can then be stored in a freezer for up to 40 years.

Here are a few links and you can find more by searching for "ultra dry seed storage"
http://www2.bioversityinternational....n/243/ch04.htm
http://www2.bioversityinternational....n/243/ch09.htm
http://www.seedcontainers.net/update...re_urgent.html
http://www.seedcontainers.net/a_guid...servation.html



The desiccant is an important step in the cool and dry storage. It will absorb any free moisture that sublimates out of the seed.

Please note that I am specifically talking about tomato seed. Different kinds of seed have different requirements. For example, many tropical seed must NOT be stored cold. Here is a partial list of common garden seed that should be stored dry in a freezer for long term:

Legumes (Bean, cowpea, pea, runner bean, peanut, etc)
Corn (Maize, Teosinte)
Brassicas (radish, turnip, broccoli, cabbage, etc)
Solanums (tomato, pepper, potato, eggplant, tomatillo, etc)
Curcurbits (cucumber, watermelon, cantaloupe, etc)

One huge warning, be VERY careful that seed are fully dry before freezing. For example, peanuts that have the least bit too much moisture will be destroyed by freezing. As a rule, it is best to place seed in a sealed container with desiccant and leave it in the container at room temperature for 3 days to a week so the desiccant can absorb as much moisture as possible. Then place the sealed container in storage.

That brings up the question of what constitutes a sealed container. A ziploc bag is not a sealed container, but it will work just fine with beans and corn for storage up to 5 years. If you need to store seed more than 5 years, then use a glass container with a solid metal lid. If you need to store seed more than 10 years, then you need some glass tubes and a torch and a lot of practice.


DarJones

[Too Tall Toms]

This is excellent information. Thanks.

[tam91]

Just curious - why is a ziploc bag not a sealed container? That's a surprise to me.

[Too Tall Toms]

The seeds I got from Tatiana's came in little plastic bag. Should I put them in something else?

[Fusion_power]

ziploc bags are porous. You can't see it, the pores are microscopic. Over time, the ziploc bag allows moisture to penetrate.

Ziploc bags are fine for short term storage, anything up to 3 years or so. But if you want your seed to last longer than that, then you need to put them in a sealed glass jar. This is why I searched far and wide to find glass jars with glass lids and rubber seal rings.

You can place the ziploc bags in a sealed glass container with desiccant. Then it does not matter that the seed are in ziplocs. They are inside a sealed container.

If you read the linked articles and others you can easily find, you will find that the reason for freezing the seed is in part to protect them from fungi that attack seed and eventually cause sterility. Fungi only live in the presence of moisture. Stored seed represent a food bonanza to many species of fungi. Stopping the fungi is one reason why the seed are ultra dried. Stopping the fungi is one reason why the seed are stored in a freezer.

DarJones

PS. I spoke with a professional tomato grower today and asked him about storing tomato seed. His reply was 55 and 55 meaning store them at 55 degrees with 55% relative humidity. For longer term storage, store them at colder temperatures. Tomato seed does best at 4% moisture in the seed. A simple way for most home gardeners to store tomato seed is to put them in a glass jar in the refrigerator which stays about 37 degrees (2 degrees C).