If these don't do anything might be easier just to pot any future batches attempted in fall and place where will be exposed to temp. below 40F in a garage, sunporch or cold greenhouse and let them come up when they want to after the weather warms.

If these were hard and dry seeds they will probably not come up as readily as if sown while still soft, there is supposed to be quite a difference. Seed that has become hard and brown before sowing has entered a dormancy.

Hello Homegrown,

You probably do need to be patient with these seeds, even to the point of giving them another year. Sometimes they can take two (or more) overwinterings to break dormancy. And if you can find someone who will let you pick seeds from their trees, you will probably have more success with seeds gathered when they are just starting to turn brown and then planted before they dry out. I like to overwinter them in a cold frame. Also seems to make a difference which tree you get them from.
Good luck,
Fred

I wouldn't recommend growing any Japanese maples from seed. Who knows what the seeds are intil the tree is a few years old. Acer Palmatum-Rootstalk is fine to gro from seed all other should be grafted. I'd recommend talking with Sooner Plant Farm http://www.soonerplantfarm.com or Pacific Coast Maples http://www.pacificcoastmaples.com which both specialize in Japanese maples.

Here is a link that might be useful: Pacific Coast Maples

Patience as mentioned above has merit. Collecting seeds around the first frost and placing then in a bed of sand/mulch exposed to the elements in a sheltered location will give you seedlings that appear in April in one or two years. They precede other maple seedlings in the central MD area when temps are in the 60s. I cover the container with netting to prevent squirrels from disturbing the surface.

It is fun! 4 years ago I started with a few hundred seeds, got approx. 50 seedlings. I lost some, but last year I gave away most of it to friends, kept maybe 10, different, non of them has dissected leaves. Some are 4-5 ft tall now, still in pots.
You can't compete with the the grafted ones, but if you have big garden , enough room for them, why not to try?

homegrown1.
Well, you get my first post on this site. Several years ago I decided to try growing some JM's from seed. I collected several seeds from a variety of trees in the central Vancouver Island area. I did as you did, put them in a jar with sand and maybe vermiculite [not too sure about that, the old memory doesn't always work] then planted the seed in flats and just left them outside. I got about a 25% success rate, which I considered very good, as really I had not much idea what I was doing. Gave about 25 trees away and have perhaps a dozen left, still in pots. Those that were planted in the ground, the ones I gave away in other words, are all doing fine. Mine still in pots are still OK, but are nowhere near the size of the others.
So the one thing that seems to me to be a bit odd, is that you put the seeds in an 80F greenhouse! I think if they had been outside in a much colder environment, they may have had more success.
Did you notice that when you took the seeds from the fridge if any of them had started to germinate? Several of mine had.
Did any of them eventually come up?

in fall of 2010 I collected a bunch of seeds from a favorite garden place and this spring (2011) I have several dozen seedlings coming up.....it's awesome....
a few are nishiki-ed (lol) and some are dissected.....there is a nice variety.....this year I'll be sure to identify the tree's I get them from.....

just my 17 cents