I was wondering how to test the viability of seeds. Are there different tests for different seeds or is there one test that works for all seeds? Also, is there a way to tell if seeds need to be stratified or not?
You provide a certain number seeds with the conditions they need to grow and see how many sprout. Number sprouting divided my number planted will give you a germination percentage. Typically at home I do 10 on a moist paper towel in a plastic bag.
Typically seeds need stratification are native to areas of the world that have winters where the plant would die if it started to grow in the fall. If you had seeds that you had no idea what they where then you'd have to start experimenting. The best way is to look it up.
If you Google the plant's name, information as to hardy zone should pop up. In general, most plants that are hardy do need stratification (moist and cold). Others need stratification with flunctuating temps.
Edited to add that the Deno method is a great one to test seeds with. I had seeds stored in my shed for 6 years that I forgot. They weathered heat and cold. I used Deno to test. They were still viable. If stored dry, seeds can last for years.
Here's another good site. Although I have used the above mentioned seed germination sites, I think I like this one the best. It goes into a little more detail and explanation. This especially helps if you are new to seed germination.
I was able to download it as plain text and now I can search it offline.
BTW, this is also a helpful site for starting seeds, including difficult seeds. It breaks each genus down into different advice for different species. It also has a good article about "best" seed starting temperatures: speed vs %.
I think I will try to down load and print out the Back Yard Gardener Seed Information that was the old T & M booklet. The T & M booklet is no longer available. I don't think I want to chance losing the Back Yard Gardener site.