However, I will simply clarify that I don't really keep them cold AND soak them. They are soaked intially and then simply kept moist inside a bag with holes. There is quite o bit of air around the seeds and bags. Since the seeds have been rehydrated and are metabolizing (if only very slightly to mature the embryo and degrade the germination ihibitors) oxygen will be necessary.
So one must be careful how long they are soaked. Fresh air or water (oxygen) needs to be refreshed to some extent.
I would have to disagree with you on the temperature cycling not being important and will clarify. Sure it probably isn't necessary if you don't care about ALL of the seeds coming up the first year. But that is what I want and temperature cycling achieves that for most crosses and increases my germination percentage, some very significantly. There also may be other factors interfering with your observations (i.e. the soaking or choice of parents). The cycling doesn't work for all crosses and only helps those seeds of a cross that haven't germinated through normal stratification. So the percentage of seeds from a cross that germinated from temperature cycling might very likely be lower compared to those that germinated from stratification alone. But the more seedlings from a cross the better, right?
There is too much reliable data and my own personal observations for me to discount the method for Iris or other species. An example is Verbena bonariensis. It will absolutely not germinate without temperature cycling (I've tried).
Raleigh, NC Zone 7
> I know from experience, which I see Paul has seconded down string, that the seeds don't mind being cold and soaked at the same time.
> For what it's worth I am less convinced that the repeated cycles of warm and cold are important. I think there might be some muddy data between cold enough and wet enough, or enough time passed since the last day at x temperature.
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