viability of seeds

Is there a chart somewhere that tells how long different seeds are viable? I have found them for vegetables but not for flowers.

There is no website that has info about viability of seeds of a lot of plants/flowers.
You need to search for almost every plant on the Internet.
Since I trade and sell my seeds, I started to investigate the viability of seeds, but it's very hard to get any information.
I prefer to give an 'expiry 'date on my seedpackets, so I made a small dbase of everything I found about viability of seeds.
In general all real annuals and a lot of biennuals are viable for at least 3 years. That's nature. All plants want to survive and some years are better for seeds to germinate and some years are very bad. But there are always exceptions.
And about perennials: the seeds may be viable from just 4 weeks up to 100 years!
But even the Internet doesn't give always the right viability. I read about the Dimorphoteca sinuata (a perennial in warm climates, annual in cold climates) and learned the seeds were only viable for a year. But this year I sowed 2 year old seeds and I had a great germination. Will try it next year again if the seeds are 3 years old.
It's very important to store the seeds in the right way. Most seeds must be stored dry and on a cool and dark place, but some (short viable) seeds need moist storage.

If I can find the time, I will publish my investigations and experiences on a list of 'how long are seeds viable' on my website www.seedsite.eu late autumn or early winter.

Kind regards,

Jonna

Thanks so much. I have had trouble with sea thrift, Black Cohosh, and dwarf zinnias lately so I've been frustrated. But I'm not sure of the age of some the seeds I get in trade although I think most gardeners are careful about that.

Here's a table that lists some vegetables and some flowers.
They stress "under ideal stoage conditions".

seed viability table
http://www.hillgardens.com/seed_longevity.htm

But I agree with jonna: "But even the Internet doesn't give always the right viability. "

At least, you can get three different answers for any given type of seed.

Corey

Wow, that link is quite informative.

I'd like to begin storing my seeds in canning jars once they're properly dried, but I have no way to measure humidity of the dried seeds. And where would one purchase a dessicant product?

"Silica gel" for drying flowers is available at many craft stores. I think I found 1 1/2 pounds for $7-8. It looks like powdered sand, and I personally avoid breathing the dust.

I put a few tablespoons into a kraft paper envelope ("coin envelope") and staple it closed with 2-3 staples, so little comes out even if it tips over (but I prop it up between seed packets. Humidity goes right through paper.

You can also put it intop a plastic baggie and leave tha open, but I like the "no-spill" method.

It lasts at least many months in a jar that stays closed, or can ahndle some numbe rof opebnings, depending on the size of the jar and your humidity. I think I open and close a jar 2-3 dozen times before one envelope is used up.

The "gel" can be regenerated by baking in the oven at a high temperature (but take it out of the paper envelope for that!). I think that temp was around 400 or 450 F, but check the side of the jar to be sure. Spread it thin while baking, and seal it back up in glass while hot to avoid re-absorbing water.

I plan to go through my pound-and-a-half a few tablespoons at a time, and regnerate it all at once.

I started buying an expensive jar of "Drierite", that turns from blue to pink when used up, but the cheaper silica gel seems to last longer.

Corey

I got some hunidity-indicating cards when I bought the Drierite (from a company of the same name). They were cheap: maybe 50 cents each for the fancy ones that indicate 10% - 20% - 30% etc. I got some even-cheaper ones that just go from dark blue to pale blue to lavender to pinkish somewhere around 20-30% RH.

I wish I had bought lots more, especially of the fancy ones!

I think I heard that ULINE sells them, but I haven't checked.

I read about a clever trick on some seed website: put a few strips of ordinary newspaper in the jar. When you open, rub the newspaper in your fingers and crumple it a little. If it feels brittle and "crunchy", it is very dry. If it is limp and "squooshy", it is NOT dry.

But you have to open the jar to check.

Without any humidity indicators, I would just replace the silica gel once or twice per year - or every 25th ofr 50th opening in humid weather. Probably, opening it in a dry, heated house in the winter doesn't suck in any humidity. Opening it in a New Jersey summer fills the jar with very humid air, and hot humid air holds a lot more water than cold humid air.

ON THE OTHER HAND

I asked a local Master Gardener in the Pacific Northwest, and she asked around the other MGs. Their consensus was "we don't worry about humidity and our seed seems to last pretty well".

They dry seed well before storing it, and store in paper or plastic.

I may be paranoid, but it rains every day, most of the year, here, and I store seeds in plastic Ziplocks. Those are not impervious to humidity, but slow down its transfer. So I like the dessicant.

Ny guess is that fewer than 10% or DG members bother with dessicant.

One warning: some people store seeds in the vegetable or "crisper". That is the part of the fridge engineered to keep lettuce and such MORE HUMID than the rest of the fridge. Fact, you can look it up. It holds humidity IN. Or deduce it: lettuce and veggies get limp as they start to dry out, and you sprinkle water on them to make them turgid and "crisp". Storing seeds there is storing them in an extra-humid spot. Yet many do it but still have "fine" longevity.

(On the other hand, being semi-sealed, shouldn't it prevent excess condensation on the contents when you open the door? I don't know why, but it works the other way: a shelf in your fridge stays drier than the vegetable drawer "crisper".

What drives me crazy is that many people throw some seeds in a paper bag in a shed or garage that gets hot, cold and damp. And it still sprouts years later! That isn't going to stop me from doing my "science project" my way. At least, not until I get tired of doing it my way.

Corey

I keep my seeds in the fridge until I need them. But not in the crisper. I call those bins the "rotters" because I forget what's in them. So I use mainly for potatoes and onions.

Sea thrift seeds are viable for at least 2 years, Zinnia's for at least 5 years. About the Black cohosh are several reports, most of them tell only to use fresh seeds.

The list I'm working on will only contain scientific investigated viability of seeds or the viability of seeds I could determine myself.
When I searched the internet about Salvia seeds, I found out they would be only viable for 1 year, but I found out Salvia seeds are viable for at least 2 years, sometimes even sprout better after 2 years. Will try to find out how 3 year old seeds will germinate.

In the meantime you can ask me about the viability of seeds, but I must say the most scientific investigations tell about non hybrids.

And if someone has experience with the viability of certain seeds, I would really appreciate to hear that, so I can make my list longer.

Jonna

You are great help Joanna. I am trying some French Hollyhock seeds now. Of course, they won't bloom this year, but it's good use of the greenhouse to start perennials now that everything else is out of there.