No, there's no expiration date (at least for most seeds). I would expect fewer germinations, but that obviously didn't happen with your tomatoes. :)

I think you should be able to share them (or trade them!) as long as you say up front they are a few years old, but commercial seed.

Lisa

Jan,

There really are no odd questions here!

There is no expiration date, but they slowly lose viability over time. So, every year--and especially after they are 3 or 4 or 5 years old, you'll see progressively lower germination rates.

You can keep them viable longer by storing them in airtight containers in a cool, dry place or by storing them in a freezer (also in airtight containers).

The main two enemies of stored seeds are high moisture and high temperatures, and the two together are a bad combination.

Also, one problem with stored seed that we seldom discuss is that the seeds do lose vigor while they are in storage. So, even though "old" seed will sprout, the plants may be less vigorous if they are from older seed than they would be if they were from fresher seed. That's why serious seed savers, like George, grow out their seeds periodically--usually on a specific rotation like once every 3 or 4 years or whatever. You have to constantly renew your seed supply over time because of that loss of vigor.

Seeds that have been properly processed (dried down a moisture level of around 8% or even less) often maintain not only good germination rates but good vigor for quite a few years.

Dawn

Dawn-

How do you determine the moisture content of seeds?

Bruce

Bruce,

It depends on the type of seed, but almost all seeds that have been dried down to 8% or less will break and not just bend if you bend one in half with your fingers. A seed with more moisture will bend or fold in half, but not break.

A properly dried corn or bean seed, for example, will shatter when you set it down on a concrete garage floor or driveway and hit it with a hammer if it is dried down to the proper moisture level for freezer storage.

The reason they have to be so dry before put into freezer storage is that seeds with a higher moisture level can be damaged in the freezer. At higher moisture levels, the excess moisture in the seed expands when frozen and that expansion causes cell membranes to rupture.

And, some small seeds can and do dry down to very low moisture levels--as low as about 4-5% because of their lower mass.

Even seeds that have been properly dried and properly stored in airtight containers in the freezer can sometimes suffer from damage as they are brought out of the freezer. It is best to take them out of the freezer and let them sit unopened either all day or all night before you open the container. If you open up the container before the seeds have naturally warmed up to room temperature, moisture can condense on the cold seeds and rehydrate them. Also, after removing the room-temperature seeds from the container, reseal it and put it back in the freezer. Finally, it is best to let the previously frozen seeds sit at room temperature in a cool, dry location for a few days before you plant them. That way, they are slowly absorbing small amounts of moisture from the air over time which is an easier adjustment that going from cold dry-storage in the freezer to moist soil in the ground (or in starter flats ) all in a day or less.

Dawn