Hi, everyone! I'm a new member and relatively new to bonsai (started a couple years ago). When I started with my first few trees, I quickly put them into bonsai pots and started pruning and refining, etc. With my new trees this season, I want to give them more time in development to grow their trunks and manage their structures. I got two new trees today from a nursery, both quite small--a Hokkaido Chinese elm and a barberry. I'm going to move them into larger nursery containers, but my question is: What kind of soil should I use for development? Is a partial organic mix better than the inorganic soil I use for my bonsai in refinement? The nursery mix seems to be potting soil with pine chips. Is that just standard nursery practice for any plant, or is that the kind of mix I want them in for development? Would love to hear what you all do, and any other advice on good development practice.