Propagation: Stolen Idea!, 1 by

wrote:
For Japanese Maple, seed should be collected from the tree before it dries, then sown directly outdoors for germination the following spring.

These seeds require stratification, meaning flunctuating winter temperature to break them out of dormancy. It is the same with Iris seeds, which I sow.

I would soak the seeds over night in hand hot water. Then sow the seeds in a plastic container, like a shoe box from Walmart. Plant the seed 1/3" deep of its size. Leave the container outdoors on the north side of a building. Melt drainage holes with a hot nail. Premoisten the potting soil, then keep the container covered.

Below is a photo of this years harvest of Iris seeds. Any perennial can be sowed the same.