But it doesn't apply to all plants, have you come across any that should not be treated like this?
Yes, you are correct, not all species can be treated the same but I do this to most deciduous trees that I grow. Tridents are among the hardiest. I would leave roots a little longer on Chinese elms and Japanese maples and most other species as well, but not by much.
There has been plenty of threads showing that olives can be cut even harder than this and still survive. Our club has collected lots from roadsides and paddocks and had close to 100% survival.
You are already probably aware that pines will die if all the branches are cut off like that but I still grow them in the ground roughly the same - prune early to get lots of branches and leaders, allow them to grow freely for 1 or 2 years then remove surplus growth to leave the best trunkline and shoots that will become branches. I still prune the roots of conifers quite hard (not as short as the photos above though) but there is nearly always some smaller feeder roots that you can leave to keep the tree alive while it recovers. Conifers I have used include: JBP, JRP, Chinese juniper, gingko, mugho pine, swamp cypress and dawn redwood.
The banksias I have tried have also been treated similar to pines. I have lost a few but survival rate is improving each time I try. Callistemon can be treated similar.
I have tried a few other natives with very poor survival rates, even when leaving far more roots so much more work needed there.
