Getting a handle on Viability

[Got Worms?]

As sure as the Earth is a fertile ball of dirt covered rock, revolving around a life giving heat source, I know, that everyone that has ever started their own plants from seed has, at one time or another, while going through their seed, asked themselves this inevitable question; "Are these still good?"

Now, after 40 years (more or less) of gardening, I still can't answer that question. Not without doing a viability test.

I have seen viability charts all over the 'net, but they vary, depending upon which "expert opinion" you wish to put stock in and which particular plant you may be looking to grow. As an example: take spinach; Fedco says 2 to3 years, Johnny's 1 year, Vermont Ext. 3 years, and the Iowa Ext. says they stay viable for 5 years. No wonder I can't bring myself to throw away "old" seed.

To add more confusion to that, there is also the storage factor. How the seeds are stored can actually extend (or cut short) that spark of life within the seed that we call viability. Humidity and temperature are the two most important determining factors in the storage of seeds. The seeds, if stored in a low temperature and humidity environment (with the least fluctuations), will maintain their viability best. Beyond that, at least for me, there be dragons.

Sometimes, when that spark of life whether intentionally or unintentionally has been preserved over an extended period of time (but is very weak, like a very sick and dyeing bird) it can be nursed back to health to germinate and grow (fly again) with the right care and handling. And some other times what's dead is dead. A fragile thing.

If I knew all there was to know about viability, I wouldn't have all these piles of seeds. If you know something that I don't, please, I could use the room in my refrigerator.

Charlie

[rags57078]

just buy another refrigerator

[Got Worms?]

Originally Posted by rags57078

just buy another refrigerator

Thank you, Rags, but for more than one reason, I'm looking to further my knowledge, rather than put more electrical equipment on the grid.

Charlie

[Doug9345]

You did a good job of summing it up. First I think most of the number published are times that correspond to having a germination rate high enough to sell the seed. It's not the time that says you'll get no more of them to sprout. The little it of reading I've done on it seems that seed life is more related to the build up of what I'm going to call waste produces than it is of the seed running out of energy.

[Got Worms?]

Interesting, I knew that flowering plant species drew their energy from "food" (starches) stored in the endosperm, but never really looked at it in the biological sense that as the starches are consumed, waste will be created. So, it stands to reason that by lowering the temperature and controlling the moisture, you are basically causing a slowdown in the seeds metabolic rate, which could be looked at as a sort of suspended animation. Less food eaten; less waste build up; longer life. Thanks Doug, that helped me to understand a bit more about the process.

[Doug9345]

I think that beans point this out. Beans are nutritious way past the point where they will germinate.

This is about oak tree seed but it gives some guesses about why seeds loose vitality.
http://treephys.oxfordjournals.org/c.../1147.full.pdf

[Tormato]

Nice timing on the post, Charlie.

It's about time for me to dust off my Ace 55 (1965) seed. It was stored in a deep freeze (Auburn U.) for about 45 of it's 50 years.

Gary

[bower]

There is a way of getting rid of old broccoli, turnip, cabbage, cauliflower, radish, spinach, herb...... seeds which you're clinging onto because they might be viable.

I resolved in the off season past year, that every old seed I couldn't part with, that could be consumed as a sprout, would be sprouted and duly consumed. Results: not enough sprouts to make a sandwich! All I got was the bonus, more room for fresh seeds. Fewer feelings of doubt and compulsive attachment to rubbish... empty packets out!

[Got Worms?]

Doug, although this study on tree-seed physiology is a bit technical for me and my layman’s brain (laym brain for short) I did come away with a few tidbits Like the process of desiccation (drying) giving way to higher concentrations of sucrose (sugar) and this in turn has a protecting effect on the cell walls. Duh. This reminds me of apple crisps.

But this study is on recalcitrant and orthodox oak species which is even more muddling and leads me to believe that it was "purposely written so", mainly to justify grant money. I find it hard enough to get through technical data without the authors just quoting all the other conflicting studies, while showing their own and not being able to make any clear conclusions, other than; "an un-identified metabolic failure is responsible for the desiccation sensitivity."

I did retain a little info through some of the references made, but it was hard going. Maybe it's just me. I'd like to make sense out of it, but not being an academic...it just raised more questions. Mainly "Who is giving money for non-comprehensive studies like this?

What I get out of this is a lot of info, some useful, some conflicting and none conclusive. Still it's better than a poke in the eye. Thanks again.

Charlie

[KarenO]

For a tomato seed collector (which I admit to being)it is easy to renew and revive old open pollinated seed; and that is by growing out one plant, saving seed again and once you have new seed you can get rid of the old. If you keep track of your seeds by year and grow out a few of the oldest ones each year, you will have a fresh supply and not need to store old ones hoping they may germinate for you ten years down the line. If it was one I didn't especially like and will not grow again, then giving those away is a good way to keep the collection down to a manageable size.
Says she with a current total of 317 kinds ...
Karen