Congrats. You're a father...or mother. Now, first and foremost, nothing will kill a seeding faster than potting it up with garden soil. It will turn to cement. Search this forum for potting mixes.

tj

Could you possibly put your growing zone information in your profile so that it shows when you post?
I find it difficult to process posts without the context of where you are.
And yes, I know I can see it if I click on your profile- my position remains that I shouldn't have to :)

Congrats on the seedlings.
Did you do a anything special in the way of seed prep?
What kind of maple do you have?
Do you know it is is self pollinating or what other maples you have in your neighborhood?
It will be interesting to see what they turn out to be!

I'm sorry, I'm in zone 8 in central Cali. I'm not too knowledgeable about Japanese Maples so all I know is the one in my front yard is a green one, and it has lots of seeds growing on it right now. I didn't do anything for seed prep, the only thing I can think of is a few weeks ago I pulled out these ugly bushes that were around the tree itself and I soaked the dirt around it to pull out the roots from the bushes, which left the dirt wet and loose. So yesterday when I went outside to pick some seeds to prep in the fridge, I found some already sprouting! Now the trick will be to keep them alive lol. There are a lot of other Japanese around my neighborhood both red and green, so I am excited to see what the seedlings will be.