For reference, this Japanese maple forest was pot-grown from seeds for the last 6 years. There are 55 trees here, I got them very close by letting the seeds sow themselves. I set a grow box under a maple tree, and let seedlings grow how they wanted to, so this is a bit of an experiment. The biggest tree on the right I let grow almost unrestricted every year to be dominant, then cut in the fall.
Several groups of trees were trained and then positioned in the pot, I've added to the forest over the years.
I plan on sowing some fresh seeds this December for the contest, this looks like fun!