If you took the root cuttings and had reasonable success, then that should give you an idea of when. They can be root pruned fairly aggressive but must stabilized when they are transplanted.
@Adair M, I'm glad you posted the last tree because it is the best visual explanation possible. If this tree were grown with small tree technique it would never or at least in the next few hundred years have that proportion. Now if a small tree was the objective, it would would have lost all...
13, by all means, do what you've had success with. Field Capacity is a term that separates moist from wet media. When preparing the media for stratifying take a handful and squeeze it tightly. The goal is to have 1 or 2 drops of water come out.. More is too wet and subject to rot. Less possibly...
13, older seeds can be tough to get good percentages. the warm stratifying is important! Soak the seeds at least 24hr and put in a container with moist (not wet) media. I use white orchid moss but sand, peat moss or any media that can keep a consistent moisture will work. Place in cabinet...
Andy, Dave and Brian made excellent comments about knowing what size tree you want. That dictates how to go about pruning/training.I worked at Telperion on the trees Adair showed and they were grown to be larger trees. Principles are roughly the same for either large or small but there are...
Roxie Eslick, the caretaker, the foreman, the person at ground lever lost everything! All personal possessions, her house at the farm, her job. I’m not technologically astute to launch anything but Roxie needs this also!!
Roxie’s home
Like Frank and Wire said, there is too much confusion in trying to “classify” growth tendencies when just observation of a given tree is enough. The genetic diversity in Japanese maples alone is a books worth of study in pruning technique.