I'm trying some Styrax Japonicus seeds that I got in a trade this year. The person I traded with said you need to scarify the seeds before soaking since they are so thick. She thought that scarification was more important than soaking.

I also found a journal article that had studied various methods of germination and they found that one to two months of warm stratification followed by at least two months of cold would break the dormancy. I don't have a link for the full article but the abstract sums it all up.

I know this isn't the exact same tree, but this should still help.

Good luck!

Here is a link that might be useful: Styrax Japonicus Germinatino

Clothiers: Styrax obassia , Fragrant Snowbell Tree ,zone= 6 , difficult, if at all (meaning germination, and I don't remember coming across that particular notation there in several hundred types of seed I've looked up)

Seed Site: Sow outdoors in Autumn for germination in 193 days. (Seed Site is mild winter UK, so that would be warm moist, followed by moist chill, followed by cool moist)

Thank you both for the great info! Shouldn't be too hard.

I've also read that the warm period first was very important. Personally, I've had no luck with them. If they ever grew, they are nameless weeds in the yard now as I dumped the pots out and I had a lot of seeds.
Not to discourage you. You should still try. If nothing ever grew, there wouldn't be any around.

I can tell you that my Styrax japonicus readily self sowed under the tree...enough so that I brought a dozen seedlings south with me when I moved, and had to pull lots more. I'm thinking that a good stratification program might help you, although I know we are talking about two different plants here.....Good luck to you. The silverbells (and I'll throw in Halesia here) are really neat trees!

My obessia seeds sprout right in the ground.Then I put them in my holding bed until I find a place for them.