I would think that the act of forming a block of soil that would hold together enough for planting would automatically exclude a lot of important air space. I know I've seen them in use in the past. I will keep an eye open for those and try to let you know if I find one. I hope you can help us. We have a marvelous Kousa Dogwood on our property that we are trying to propagate.
Books state that propagation is by seeds sown when ripe in a cold frame.
Examination of the seed cases reveal a seed like substance inside the large green case and virtually nothing but pulp in the red cases. So what exactly does the seed per se look like. Is it the whole case or just a component of what is inside. Numerous trips to the library have not produced the necessary information. Local greenhouses don't seem to want to take an interest in helping the average homeowner.