Marg, you may want to watch your seed sources, article by U of Minnesota cautions " The species can be grown from seed, although locating viable and true-to-type seed can be difficult. "

I see Gardens North has theirs moist packed. As sellers of very high quality seeds, they don't do that without reason.

"Gardens North seeds: ACER pseudosieboldianum (Moist Packed)Seed has been moist-packed to preserve viability. Cold treatment required."

Plant Explorers propagation notes: "Fresh seed - Will be cold moist stored. Place seed in tepid water, sow sinkers immediately. Soak floating seed 4-24 hours until it sinks and sow immediately. Sow thinly at 6 mm deep in a sandy peat layer; tamp firm. Cold stratify for 60-120 days. Keep moist. Add a thin layer of fine mulch. Don't let germinating seed freeze, dry out or migrate onto the medium surface as this is fatal. After cold stratification period is over, expose to spring conditions to promote germination. Good indirect light is best for seedlings"

Thanks for the info. Marg