Absolutely one of my favourite containers for newly collected trees is the Anderson flat, deep propagation version. roughly 15 by 15 by 7 inches with a mesh bottom.
for drainage one can nest this type of flat or place on a porous surface. here is a Shimpaku dug and placed in the deep propagation Anderson flat.View attachment 324382
Thats a pretty nifty container. I'll check that out for sure. One last question. When I transplant these for the first time into a box is it ok for me to prune as well? Or do I need to let them stay as they are for a period of time before I prune and shape? Thank you again!