The usual way to do this is to do frequent root pruning in a normal pot. Do you think the air pruning action of fabric pots would be enough to do this? I have limited space and don’t keep any mother plants right now, but just read about this and was thinking fabric pots might make easier. I’ll probably try it out next year.
I use (homemade) fabric pots for my bonsai moms. Some have been that way for a year or so. Eventually they get too tall and you either need to replace them with a fresh clone, or try and cut the root ball down. I usually just replace with a healthy clone.
You can keep a mom in a fabric pot for several months easy. And when she gets too big take some clones and mulch the mom. I used to have a mom in a 1gal smart pot for 4 months till i chopped and cloned her.
This is a good topic. I was wondering this same thing. I just got done mixing up my soil and am getting ready in the next week to up pot and I was wondering whether or not to put the moms in fabric pots… Good info, it will come into use soon!!!