Posted: 10/04/2013 at 08:56
This site has a lot of info.
I also have a book called 'Growing from seed' by Karen Platt.
I think everything can be planted ripe. The problem is getting the surroundings right. That's hard for tender plants. I don't grow tender plants and sow almost everything as it ripens.
Do what happens naturally for hardy plants, sow it when the plant is dropping it and keep it as it would be kept natually, under snow, wet, cold whatever. It's how things have evolved to survive
Ranuculaceae, apiaceae and primulaceae all benefit from the ripe sow/chill as do paeonies.
There are always exceptions but if it's in a berry or a pod I stratify it.
Seeds naturally germinate and many will whatever you do with them.